Production method of X100 steel grade elbow pipes and pipe fittings

The invention relates to a production method of X100 steel grade elbow pipes and pipe fittings. The steel used for producing the elbow pipes and pipe fittings comprises the following components by mass percent: 0.12-0.20% of C, 1.35-2% of Mn, 0.3-0.5% of Si, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.015-0.05% of Al, 0.002-0.005% of Ca, less than or equal to 0.007% of N and the balance of Fe, wherein Nb, Ti, V, Mo, Ni, Cr, Cu and B can be added optionally. The production method comprises the following steps: melting the materials, rolling under control, and air cooling to obtain a hot-rolled sheet steel; performing molding and longitudinally-submerged arc welding to obtain longitudinally-submerged arc welded steel pipes; and performing induction heating, annealing, and heat treatment to obtain elbow pipes, or performing thermo-mechanical molding many times to obtain pipe fittings. The elbow pipes and pipe fittings produced with the production method provided ...

Preparation method of continuous expansion pipe with high strength and high plastic elasticity

The invention relates to a preparation method of a continuous expansion pipe with high strength and high plastic elasticity, comprising the following components by weight: 0.03-0.12% of C, 0.17-0.40% of Si, 0.80-1.90% of Mn, not more than 0.010% of P, not more than 0.005% of S, 0-1.0% of Cr, 0.10-0.50% of Mo, 0-0.30% of Ni, 0-0.05% of V, 0-0.03% of Ti, 0-0.30% of Cu, 0.01-0.06% of Nb, and the reset being Fe. The method comprises the following steps: melting all components via an oxygen blowing converter, precisely melting outside the converter, degassing in vacuum, continuously casting, roughly rolling and precisely rolling so as to obtain a hot rolling plate coil, shearing into steel strips, welding oppositely, connecting the steel strips, and using the steel strip to produce a direct gap resistor weld steel pipe. The lowest yield strength is 485-760MPa; the lowest extension ratio is 25-35%; and the impact power is not less than 40J.

Analytical prediction method for decompression wave of high-pressure gas transmission pipeline

The invention relates to an analytical prediction method for a decompression wave of a high-pressure gas transmission pipeline, which is applied to the technical fields of breakage control and safety guarantee of high-pressure natural gas transmission pipelines. The method comprises the following steps of: selecting corresponding state equations according to different gas qualities, namely four state equations and combinations of SRK (Saove-Redlich-Kwong), PR (Peng-Robinson), BWRS-PR (Benedict-Webb-Rubin-Starling-Peng-Robinson) and BERS-SRK (Benedict-Webb-Rubin-Starling-Saove-Redlich-Kwong) at initial pressure P1 and temperature T1 before breakage of a point of the detected pipeline; and calculating fluid characteristics of density, fugacity, constant-volume heat capacity, constant-pressure heat capacity, specific heat and the like of fluid at isoentropic point pressure temperature, which are used for judging the phase state of the fluid in the pipeline, describing the characteristicsof ...

Preparation method of X80 bent pipe and steel for pipe fittings

The invention relates to a preparation method of an X80 bent pipe and steel for pipe fittings. The X80 bent pipe is prepared from the following components in percentage by weight: 0.1-0.25 percent of C, 1.3-2 percent of Mn, 0.3-0.5 percent of Si, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S, 0.01-0.05 percent of Al, 0.002-0.005 percent of Ca, less than or equal to 0.0008 percent of N and the balance of Fe. The preparation method comprises the following steps: controlling the ratio of Mo to P to be more than or equal to 10 and the carbon equivalent to be 0.40-0.58 percent; obtaining a plate blank by oxygen blowing and smelting, Ca treatment, refining and degassing in a vacuum furnace; obtaining a steel plate by rough rolling and finish rolling; and obtaining the bent pipe by forming, submerged-arc welding and induction heating. The bent pipe has the yield strength of 555-705MPa, the tensile strength of 625-825MPa, the yield ratio less than or equal to ...

Alloy pipe containing 18-24% of Mn and manufacturing method thereof

The invention relates to an alloy pipe containing 18-24% of Mn and a manufacturing method thereof. The alloy pipe comprises: 0.002-0.2% of C, 18-24% of Mn, 0-4% of Si, 0-5% of Al, no more than 0.015% of P, no more than 0.01% of S, no more than 0.008% of N, or one or more of 1-6% of Cr, 0.1-0.5% of Cu, 0.01-0.6% of Nb, 0.01-0.1% of Ti and 0.01-0.3% of V, and balance of Fe. The manufacturing method comprises the following steps: casting the raw materials by vacuum melting, carrying out homogenizing annealing and hot-rolling on the casted materials so as to be manufactured into steel plates or bars; carrying out resistance-welding or hot-rolling on the steel plates or balls so as to be manufactured into pipe blanks; carrying out solid solution treatment and ageing treatment on the pipe blanks, wherein the obtained product has a uniform elongation percentage no less than 50% and a yield strength of 300-400MPa; and carrying out dilatational strain of 30% on the pipe blanks, wherein the obtained ...

Method for manufacturing composite elbow with anticorrosion function

The invention relates to a method for manufacturing a composite elbow with an anticorrosion function, which comprises the following steps of: (1) manufacturing an elbow inner layer by machining a seamless stainless steel pipe in a bending way; (2) dividing an elbow outer layer into two symmetrical parts along the central line of inner and outer arcs, and performing hot-pressing molding on the two parts by using pipeline steel plates respectively; (3) assembling together the two hot-pressed molded parts of the elbow outer layer and the elbow inner layer, and connecting together the two parts of the outer layer in a welding way; and (4) tightly combining the stainless steel elbow inner layer and the pipeline steel outer layer in an expanded joint way. Compared with an all-stainless steel elbow, the elbow comprising the elbow outer layer made from the pipeline steel can effectively control the manufacturing cost; through the method of molding the inner and outer layers of the composite elbow ...

Steel for X80 grade low-temperature pipe fitting, and preparation and application thereof

The invention relates to steel for an X80 grade low-temperature (-30 DEG C to -46 DEG C) pipe fitting , and preparation and application thereof. The steel comprises the following components in percentage by mass: 0.12 to 0.16 percent of C, 0.20 to 0.30 percent of Si, 1.00 to 1.30 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.030 to 0.045 percent of Nb, 0.20 to 0.30 percent of Mo, 0.55 to 0.75 percent of Ni, 0.10 to 0.15 percent of Cr, 0.010 to 0.030 percent of Ti, 0.0005 to 0.0030 percent of B, and the balance of Fe; and the content of Ceq is controlled to be between 0.38 and 0.48 percent, and the content of Pcm is controlled to be between 0.18 and 0.23 percent. The steel has high hardenability, the structure of the steel which is subjected to heat treatment is granular bainite or granular bainite and lump-shaped ferrite with grain size of over 10 grades, and the performance of the prepared pipe fitting can meet the requirement ofthe ...

High-strength high-toughness carbide-free bainite drill pipe and preparation method thereof

The invention relates to a high-strength high-toughness carbide-free bainite drill pipe and a preparation method thereof. The drill pipe comprises the following components in percentage by mass: 0.10 to 0.15 percent of C, 1.2 to 1.5 percent of Si, less than 0.008 percent of S, less than 0.010 percent of P, 0.6 to 1.2 percent of Mo, 0.10 to 0.15 percent of V, 0.10 to 0.15 percent of Nb, 0.25 to 0.50 percent of La, and the balance of Fe. The method comprises the steps of: performing vacuum melting and casting forming, rolling into a pipe body after the forging and perforation, heating the pipe body to between 900 and 950 DEG C, performing heat preservation for 30 to 60min, air-cooling to between 300 and 400 DEG C, performing salt bath heat preservation for 30 to 60min, and air-cooling to room temperature. The grain fineness number of an obtained structure reaches more than level 8, a microstructure is lath-shaped carbide-free bainite, remaining austenite is distributed among bainitic plates ...

Oil and bushing low-temperature powder embedding aluminizing agent for petroleum

The low temperature quick aluminizing agent specially for petroleum pipe and casing consists of metal source, activator, catalyst and stuffing. The metal source consists of 150-mesh Al powder in 10-20wt% of the aluminizing agent, 120-mesh Zn powder in 10-25 wt%, 150-mesh Zn-Fe alloy powder in 10-20 wt% and/or 150-mesh Fe-Al alloy powder in 10-15 wt%. The activator consists of ammonium chloride, aluminum chloride, sodium fluoride and/or potassium bifluoride. The catalyst consists of 100-mesh Mo powder in 0-3 wt% and La and Os 0-3 wt%, with La and Os in the weight ratio of 1 to 1. The stuffingis 100-mesh alumina powder. The aluminizing agent is applied at 380-500 deg.c to obtain aluminized layer.

Method for welding thin layer iron nickel base alloy carbon steel composite tube

The invention relates to a method for welding a carbon steel composite pipe of a thin iron-nickel-based alloy. The method comprises: processing a step on the end part of the composite pipe; adopting the surfacing of argon arc welding on the surface of the step and trimming the surfacing layer; processing a groove; adopting tungsten electrode argon arc welding to carry out three-point positioning of spot welding evenly around a welding seam, and adopting the tungsten electrode argon arc welding to carry out back welding on the root; and adopting manual electric arc welding to carry out fillingwelding and overlay welding on the upper part of a second layer of back welding. The chemical compositions of a welding material by weight percentage: 0.02 to 0.1 percent of C, 0.2 to 1.0 percent of Si, 1.0 to 2.2 percent of Mn, 20.0 to 31.5 percent of Cr, 40.0 to 60.0 percent of Ni, 8.0 to 14.5 percent of Mo, 0.5 to 2.5 percent of Cu, 0 to 5.0 percent of Co, 0.3 to 4.2 percent of Nb, and the balance ...

13 Cr oil well-pipe test material object preparation method

Method for performing expansion test of combined loads on solid expansion pipe

The invention relates to a method for performing an expansion test of combined loads on a solid expansion pipe, which comprises the following steps of: 1) preparing a sample and an expansion cone; 2) expanding an end part; 3) preparing an expansion test; 4) performing the expansion test, wherein the expansion test can be any one of the following tests: a, a mechanical stretching expansion test; b, a hydraulic expansion test; and c, a mechanical hydraulic combined expansion test; and 5) performing data acquisition and data analysis. In the method, the mechanical stretching expansion test or the hydraulic expansion test or the combined expansion test of mechanical stretching and hydraulic pressure is realized, and the displacement, speed, stretching loads and hydraulic pressure of the expansion cone and the radial deformation data of the solid expansion pipe in the process of the expansion test can be measured in real time by using axial controlled mechanical stretching loads and the hydraulic ...

Submerged arc welding wire used for X80 pipe fitting

The invention relates to a submerged arc welding wire used for an X80 pipe fitting. The welding wire comprises the following chemical components by weight percent: 0.10-0.14% of C, 0.90-1.20% of Mn, less than or equal to 0.05% of Si, 0.40-0.60% of Cr, 0.25-0.35% of Mo, 1.95-2.25% of Ni, 0.10-0.15% of Ti, 0.005-0.010% of B, less than or equal to 0.005% of S, less than or equal to 0.022% of P and the balance of Fe. In the invention, the welding wires are matched with basic sintered fluxes SJ101 and SJ102 for welding; the welding line can obtain optimal toughness after brine hardening at 890-930 DEG C and tempering at 560-680 DEG C, and the tensile strength of the welding line can be up to 660-780 MPa, and the impact value Akv of the welding line at minus 46 DEG C is more than or equal to 100J; and the welding wire is suitable for the welding of the master pipe of the X80 pipe fitting, especially for the submerged arc welding of the master pipe of the low-temperature X80 pipe fitting used ...

Selection method of test sample for steel pipe transverse yield strength test

The invention discloses a selection method of a test sample for a steel pipe transverse yield strength test, which overcomes the problem of that puzzlement is caused to the inspection and the judgment in practical engineering due to different test results by selecting different test samples existing in the pipeline design process at present, and meanwhile, the influence of residual stress on steel pipe strength, i.e. bearing capacity is taken into comprehensive consideration in the sample selecting process so as to ensure that the selection of a steel pipe yield strength test sample is more reasonable and economical. The invention adopts the technical scheme that a test sample is determined and selected through the ratio relation among the hydrostatic pressure circumferential yield strength sigmahs of a steel pipe to be tested, the tested yield strength sigmabs of a round bar sample and the tested yield strength sigmass of a platy sample; when the sigmahs is not less than 1.16sigmabs,the ...

Combined loading expansion test device for entity expansion pipe

The invention relates to a combined loading expansion test device for an entity expansion pipe, comprising a loading frame, an expansion test system, an expansion clamping system and a sensor system, wherein the expansion test system is fixed on the loading frame, and one side of the loading frame is provided with the expansion clamping system. The invention has simple and reliable structure, cansupply axial controllable mechanical tensile load of 0-2000kN and hydraulic pressure of 0-80Mpa, can realize the mechanical tensile expansion or hydraulic expansion or mechanical tensile and hydraulic pressure composite expansion test for the entity expansion whole pipe, can measure the displacement, the tensile load and the hydraulic pressure in an expansion test process and the radial deformation data of the entity expansion pipe in real time, can satisfy the expansion test of various sizes of entity expansion whole pipes or entity expansion pipe connecting structures, effectively avoids horizontal ...

13 Cr oil well-pipe test material object preparation method

The invention relates to a welding method for the collet between the 35CrMo or 30CrMo and the oil drilling vitta, bushing made by the 13Cr martensitic stain less steel. The two ends of the oil drilling vitta are machined to welding groove and many uniformly plug welding holes are machined at the position of 100mm far from the welding groove; two of tested collets are welded into the groove, which is welded with the test pipe, the inner and out of the other end are machined with screw thread to connect with the test equipment; the plug welding root is welded with the collet and the side is connected with the test pipe; or it and/or pipes are set with a ring of reinforced tendon, which the material is the low alloy high strength steel and welded with the collet and test pipe by the angle welding line. In the condition of high temperature, pressure and loading, the joint head is welded well, so it solves the problem of connecting between the 13Cr pipe and collet and has high reliability and ...

Alloy tube containing 13 to 19 percent of manganese and preparation method thereof

The present invention relates to an alloy tube containing 13 to 19 percent of manganese and a preparation method thereof. The preparation method comprises the following steps that: 0.01 to 0.3 percent of C, 13 to 19 percent of Mn, 1 to 5 percent of Si, 0 to 5 percent of Al, less than or equal to 0.015 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.008 percent of N and the balance of Fe are added; or one or more of 1 to 6 percent of Cr, 0.1 to 0.5 percent of Cu, 0.01 to 0.15 percent of Nb, 0.01 to 0.1 percent of Ti and 0.01 to 0.15 percent of V are added on the basis of the above components are added; the above components are vacuum smelted, cast, homogeneously annealed and hot rolled to prepare a steel plate or a rod stock; the steel plate or the rod stock is made into a tube blank through resistance welding or hot rolling; and after the solution treatment and the aging treatment, an expandable tube is obtained; the homogenous extension rate is more than ...

Device for testing solvent resistance on coating surface

The invention relates to a device for testing solvent resistance on the coating surface, which comprises pulley wheels, an equipment shell, a friction block, a pressure spring, a regulating bolt and a handle, wherein the pressure spring is arranged in the equipment shell, the friction block is fixed on the end part of the pressure spring, which is positioned at the opened end of the equipment shell; the other end of the pressure spring is fixed at one end of the handle, the other end of the handle is connected with the regulating bolt positioned outside the equipment shell after passing through the top of the equipment shell; and the four pulley wheels are arranged on the edge of the opened end of the equipment shell. The invention has the advantages of simple structure and convenient operation, and is a standard testing device without being influenced by anthropic factors.

Method for identifying and assessing needle-like ferrite pipe line steel tissues

The invention relates to a method for identifying and assessing needle-like ferrite pipe line steel tissues, which comprises the following steps: simplifying various ferrite tissues into ferrite and bainite; and by a heat dyeing experiment, enabling the different tissues and crystalline grains in the material to display the different contrast from white to yellow and brown, wherein the assessing of the needle-like ferrite pipe line steel banded tissue is divided into four levels. The measuring method for the ferrite crystalline grains of the needle-like ferrite pipe line steel comprises: a comparative method and a resection method are selected for the judging method of the ferrite crystalline grains; the comparative method is used for production inspection, if dispute exists, the resection method is the arbitration method; the comparative method is as follows: judging the grain size rank by comparing with a standard rating graph; and the resection method is as follows: assessing the grain ...

Method for manufacturing high steel grade sulfur resistant drill pipe by laser cladding

The invention relates to a method for manufacturing a high steel grade sulfur-resistant drill pipe by laser cladding. In the method, in the condition of inert gas insulating air, nickel-base alloy anti-corrosion material is clad on the inner and outer pipe walls of an S135 steel grade drill pipe with conventional properties by laser, a nickel-base alloy anti-corrosion layer is clad on the non-thread area of a joint, threads are processed on the thread conical surface of the joint after a nickel-base alloy anti-corrosion layer is clad on the thread conical surface of the joint, and the end part of a pipe body is oppositely connected with the joint through friction welding; the output power of the laser is 3.5-4.5kW; laser beam spot size is not more than Phi 3mm; defocusing amount is 25-35mm; laser beam scanning line speed is 6.5-7.5mm/s; the inclined angle between the laser beam and the long axis direction of the pipe body is 40-50 degree; and the delivery rate of cladding wire material ...

Rusting fracture cleaning method

The invention relates to a rusting fracture cleaning method. Cellulose acetate and acetone solution is configured according to a proportion of 12g/100ml, emulsion liquid is coated on the surface o a rusting fracture, and a film which is formed by drying the emulsion liquid after the emulsion liquid is naturally dried is revealed until the surface of the film is free from apparent iron rusting substance after multi-time binding. Through the cleaning method, a favorable effect can be realized for the fractures which are seriously polluted such as rusting, and the original appearance of major fractures can be observed, so powerful evidence is supplied to the following failure analysis of the petroleum components.

Method for welding thin layer iron nickel base alloy carbon steel composite tube

The invention relates to a method for welding a carbon steel composite pipe of a thin iron-nickel-based alloy. The method comprises: processing a step on the end part of the composite pipe; adopting the surfacing of argon arc welding on the surface of the step and trimming the surfacing layer; processing a groove; adopting tungsten electrode argon arc welding to carry out three-point positioning of spot welding evenly around a welding seam, and adopting the tungsten electrode argon arc welding to carry out back welding on the root; and adopting manual electric arc welding to carry out filling welding and overlay welding on the upper part of a second layer of back welding. The chemical compositions of a welding material by weight percentage: 0.02 to 0.1 percent of C, 0.2 to 1.0 percent of Si, 1.0 to 2.2 percent of Mn, 20.0 to 31.5 percent of Cr, 40.0 to 60.0 percent of Ni, 8.0 to 14.5 percent of Mo, 0.5 to 2.5 percent of Cu, 0 to 5.0 percent of Co, 0.3 to 4.2 percent of Nb, and the balance ...

Hermetic threaded joint of sleeve for gas well

The invention relates to a hermetic threaded joint of a sleeve for a gas well. The hermetic threaded joint comprises a threaded joint, a torque circular bead arranged between the threaded joint, and a main seal. The main seal comprises a first seal close to the torque circular bead and a second seal close to the threaded joint, wherein the first seal has a conical surface/a conical surface sealed structure; the second seal has a conical surface/a spherical sealed structure; and the torque circular bead is a -4.5 to -5.5 degree torque circular bead. The hermetic threaded joint solves the technical problem that the traditional hermetic threaded joint of a gas well pipe column frequently causes thread gluing frequently appearing, unstable seal, circular bead failure, circular bead corrosion and leakage and the like, has high seal integrity and can ensure the structure and the seal integrity of a casing string.

Special screw thread joint of high air-tight seal oil sleeve

The invention relates to a special screw thread joint of a high air-tight seal oil sleeve, which comprises an auxiliary circular bead, a first-level primary seal, a second-level primary seal, a guide surface and a bearing surface sequentially beginning from the front end part, wherein the auxiliary circular bead is a corresponding right-angle structure and has the width of 1.0-1.5mm; the first-level primary seal is a conical surface/conical surface structure, has the length of 4-5mm and the tapering of 1:7-10 and is connected to the auxiliary circular bead and a main circular bead; the main circular bead is a corresponding reverse circular bead structure and has the width of 2-2.5mm, the angle of 15-20 degrees and the transition arc radius of 0.2-0.5mm; the second-level primary seal is a spherical surface/conical surface structure, the arc radius of the spherical surface is 10-20mm, the length of the conical surface is 4-5mm, and the tapering is 1:7-10; the primary seal is connected to ...

Steel for expandable casing for oil well and manufacturing method thereof

The invention discloses steel for an expandable casing for an oil well and a manufacturing method thereof, and the manufacturing method is applied to preparing the expandable casing for the oil well for petroleum and gas industrial oil. The steel alloy material of the expandable casing for the oil well comprises the following components in percentage by weight: 0.08 to 0.2 percent of C, 1 to 2 percent of Mn, 0.15 to 0.35 percent of Si, 0.02 to 0.06 percent of Al, less than or equal to 0.01 percent of P, less than or equal to 0.05 percent of S, less than or equal to 0.08 percent of N, 0.001 to 0.005 percent of Ca, and the balance of Fe. The method for preparing the expandable casing for the oil well comprises the following steps of: preparing hot rolled steel coils; producing straight seam resistance welded steel pipes by using the hot rolled steel coils; normalizing welding lines after welding; and finally, cutting into welded steel pipes, and machining API standard threads or special threads ...

Control method of residual stress level of conveying steel pipe

The invention discloses a control method of residual stress level of a conveying steel pipe. The method mainly aims at the current situation that the control of the existing pipeline design field stays at the experience stage still for controlling the residual stress, and does not give theoretical direction for controlling stress. Based on the existing classical formula, the control method deduces and provides the stress control method and fills the blank of the pipeline design field. The technical scheme of the invention mainly utilizes a formula (1) to calculate and obtain a maximum allowable elastic recovery quantity, compares the actually-measured elastic recovery quantity with the obtained maximum allowable elastic recovery quantity and controls the residual stress level by controlling the elastic recovery quantity.

Steel used for straight seam electric resistance welding petroleum casing and casing manufacturing method

The invention relates to a steel used for straight seam electric resistance welding petroleum casing and a casing manufacturing method, which is applied to a straight seam electric resistance welding petroleum casing used for an oil and gas well in petroleum and gas industry. The steel used for the straight seam electric resistance welding petroleum casing comprises the following components in percentage by mass: 0.15-0.28% of C, 1.0-1.6% of Mn, 0.2-0.4% of Si, 0. 02-0.06% of Al, less than or equal to 0.01% of P, less than or equal to 0.005% of S, less than or equal to 0.008% of N, 0.001-0.005% of Ca and the balance of Fe. The preparation method comprises the steps of: preparing hot-rolled plate coils, producing straight seam electric resistance welding steel pipes by the hot-rolled plate coils, carrying out welding seam normalization or overall normalization on the welded steel pipes, straightening and cutting the normalized or tempered welded steel pipes into pipe segments with the length ...

Steel used for straight seam electric resistance welding petroleum casing and casing manufacturing method

The invention relates to a steel used for straight seam electric resistance welding petroleum casing and a casing manufacturing method, which is applied to a straight seam electric resistance welding petroleum casing used for an oil and gas well in petroleum and gas industry. The steel used for the straight seam electric resistance welding petroleum casing comprises the following components in percentage by mass: 0.15-0.28% of C, 1.0-1.6% of Mn, 0.2-0.4% of Si, 0. 02-0.06% of Al, less than or equal to 0.01% of P, less than or equal to 0.005% of S, less than or equal to 0.008% of N, 0.001-0.005% of Ca and the balance of Fe. The preparation method comprises the steps of: preparing hot-rolled plate coils, producing straight seam electric resistance welding steel pipes by the hot-rolled platecoils, carrying out welding seam normalization or overall normalization on the welded steel pipes, straightening and cutting the normalized or tempered welded steel pipes into pipe segments with the length ...

High temperature acidified corrosion inhibitor for oil passageway containing Cr

The invention relates to a high-temperature acidizing inhibiter containing a Cr oil pipe. A main agent A comprises the following compositions by weight portion: 25 to 35 portions of quinoline quaternary ammonium salt or quinoline derivate quaternary ammonium salt, 5 to 10 portions of potassium iodide, and 40 to 60 portions of organic solvent methanol or formaldehyde. An addition agent B comprisesthe following compositions by weight portion: 30 to 50 portions of Mannich base, 15 to 35 portions of propiolic alcohol, 5 to 15 portions of chromic chloride, and 20 to 35 portions of formaldehyde. During use, the proportion of A to B is 2-1.5:1 according to the weight portions, in an environment of 15 percent HCl+3 percent HF mud acid and 20 percent hydrochloric acid, inhibitions to super 13Cr at 100 DEG C, 120 DEG C and 140 DEG C all accord with acidizing standard requirement; and according to SY/T5405-1996 acidizing inhibiter performance test method and evaluating indicator, corrosion velocity ...

Method for identifying and assessing needle-like ferrite pipe line steel tissues

The invention relates to a method for identifying and assessing needle-like ferrite pipe line steel tissues, which comprises the following steps: simplifying various ferrite tissues into ferrite and bainite; and by a heat dyeing experiment, enabling the different tissues and crystalline grains in the material to display the different contrast from white to yellow and brown, wherein the assessing of the needle-like ferrite pipe line steel banded tissue is divided into four levels. The measuring method for the ferrite crystalline grains of the needle-like ferrite pipe line steel comprises: a comparative method and a resection method are selected for the judging method of the ferrite crystalline grains; the comparative method is used for production inspection, if dispute exists, the resection method is the arbitration method; the comparative method is as follows: judging the grain size rank by comparing with a standard rating graph; and the resection method is as follows: assessing the grain ...

Preparation method of X80 bent pipe and pipe fittings

The invention relates to a preparation method of an X80 bent pipe and steel for pipe fittings. The X80 bent pipe is prepared from the following components in percentage by weight: 0.1-0.25 percent of C, 1.3-2 percent of Mn, 0.3-0.5 percent of Si, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S, 0.01-0.05 percent of Al, 0.002-0.005 percent of Ca, less than or equal to 0.0008 percent of N and the balance of Fe. The preparation method comprises the following steps: controlling the ratio of Mo to P to be more than or equal to 10 and the carbon equivalent to be 0.40-0.58 percent; obtaining a plate blank by oxygen blowing and smelting, Ca treatment, refining and degassing in a vacuum furnace; obtaining a steel plate by rough rolling and finish rolling; and obtaining the bent pipe by forming, submerged-arc welding and induction heating. The bent pipe has the yield strength of 555-705MPa, the tensile strength of 625-825MPa, the yield ratio less than or equalto ...

Rusting fracture cleaning method

The invention relates to a rusting fracture cleaning method. Cellulose acetate and acetone solution is configured according to a proportion of 12g/100ml, emulsion liquid is coated on the surface o a rusting fracture, and a film which is formed by drying the emulsion liquid after the emulsion liquid is naturally dried is revealed until the surface of the film is free from apparent iron rusting substance after multi-time binding. Through the cleaning method, a favorable effect can be realized for the fractures which are seriously polluted such as rusting, and the original appearance of major fractures can be observed, so powerful evidence is supplied to the following failure analysis of the petroleum components.

Method for preparing polyphase structure drill rod materials

The invention relates to a method for preparing polyphase structure drill rod materials, which comprises the following compositions by mass percentage: 0.25 to 0.30 percent of carbon, less than 0.008 percent of sulfur, less than 0.010 percent of phosphorus, 0.5 to 1.0 percent of chromium, 0.6 to 1.2 percent of molybdenum, 0.10 to 0.15 percent of vanadium, 0.10 to 0.15 percent of niobium, 0.25 to 0.5 percent of lanthanum, and other elements and S135 steel grade drill rod elements. The heat treatment process comprises the following steps: firstly, performing vacuum melting and casting forming on various compositions, and treating the obtained product for 30 to 60 minutes at the temperature of between 925 and 935 DEG C after the obtained product is subjected to the production procedures of rolling and drilling of general drill rods; and secondly, cooling the obtained product to the temperature of between 280 and 420 DEG C, performing salt-bath quenching on the obtained product for 10 to 15 ...

Steel for expandable casing for oil well and manufacturing method thereof

The invention discloses steel for an expandable casing for an oil well and a manufacturing method thereof, and the manufacturing method is applied to preparing the expandable casing for the oil well for petroleum and gas industrial oil. The steel alloy material of the expandable casing for the oil well comprises the following components in percentage by weight: 0.08 to 0.2 percent of C, 1 to 2 percent of Mn, 0.15 to 0.35 percent of Si, 0.02 to 0.06 percent of Al, less than or equal to 0.01 percent of P, less than or equal to 0.05 percent of S, less than or equal to 0.08 percent of N, 0.001 to0.005 percent of Ca, and the balance of Fe. The method for preparing the expandable casing for the oil well comprises the following steps of: preparing hot rolled steel coils; producing straight seamresistance welded steel pipes by using the hot rolled steel coils; normalizing welding lines after welding; and finally, cutting into welded steel pipes, and machining API standard threads or specialthreads ...

High-strength high-toughness carbide-free bainite drill pipe and preparation method thereof

The invention relates to a high-strength high-toughness carbide-free bainite drill pipe and a preparation method thereof. The drill pipe comprises the following components in percentage by mass: 0.10 to 0.15 percent of C, 1.2 to 1.5 percent of Si, less than 0.008 percent of S, less than 0.010 percent of P, 0.6 to 1.2 percent of Mo, 0.10 to 0.15 percent of V, 0.10 to 0.15 percent of Nb, 0.25 to 0.50 percent of La, and the balance of Fe. The method comprises the steps of: performing vacuum melting and casting forming, rolling into a pipe body after the forging and perforation, heating the pipe body to between 900 and 950 DEG C, performing heat preservation for 30 to 60min, air-cooling to between 300 and 400 DEG C, performing salt bath heat preservation for 30 to 60min, and air-cooling to room temperature. The grain fineness number of an obtained structure reaches more than level 8, a microstructure is lath-shaped carbide-free bainite, remaining austenite is distributed among bainitic plates ...

Steel used for solid expandable casing of oil and gas well and manufacturing method of expandable casing

The invention relates to a steel used for a solid expandable casing of an oil and gas well and a manufacturing method of the expandable casing, which are applied to prepare the expandable casing of the oil and gas well in oil and gas industry. The steel alloy material used for the solid expandable casing of the oil and gas well comprises the following components in percentage by mass: 0.1-0.3% of C, 1.5-3.5% of Mn, 1-2.5% of Si, 0.1-3% of Al, less than or equal to 0.010% of P, less than or equal to 0.005 % of S, 0.003-0.010% of Ca, less than or equal to 0.0007% of N and the balance of Fe. The preparation method comprises the steps of vacuum melting, continuous casting and homogenizing annealing; hot rolled plate coils are prepared via controlling rolling and cooling, and the hot rolled plate coils are used for producing straight seam resistance welded steel pipes; and expandable pipe materials can be obtained via two stages of isothermal heat treatment. Threads are processed at both ends ...

Carbon steel acidizing corrosion inhibitor

The invention relates to a carbon steel acidizing corrosion inhibitor comprising the following components in percentage by weight: 43-65 percent of Mannich base, 15-37 percent of decoquinate quaternary ammonium salt, 10-32 percent of surfactant and 10-32 percent of ethanol or methanol. The use temperature of the carbon steel acidizing corrosion inhibitor reaches 140 DEG C, the applicable acid solution can be 15 percent hydrochloric acid or a mixed acid system of 12 percent chlorhydric acid and 3 percent acetic acid. The carbon steel acidizing corrosion inhibitor has favorable use effect at high temperature, but also can be used for effectively preventing the point corrosion and has little pollution to the environment.

High temperature acidified corrosion inhibitor for oil passageway containing Cr

The invention relates to a high-temperature acidizing inhibiter containing a Cr oil pipe. A main agent A comprises the following compositions by weight portion: 25 to 35 portions of quinoline quaternary ammonium salt or quinoline derivate quaternary ammonium salt, 5 to 10 portions of potassium iodide, and 40 to 60 portions of organic solvent methanol or formaldehyde. An addition agent B comprises the following compositions by weight portion: 30 to 50 portions of Mannich base, 15 to 35 portions of propiolic alcohol, 5 to 15 portions of chromic chloride, and 20 to 35 portions of formaldehyde. During use, the proportion of A to B is 2-1.5:1 according to the weight portions, in an environment of 15 percent HCl+3 percent HF mud acid and 20 percent hydrochloric acid, inhibitions to super 13Cr at 100 DEG C, 120 DEG C and 140 DEG C all accord with acidizing standard requirement; and according to SY/T5405-1996 acidizing inhibiter performance test method and evaluating indicator, corrosion velocity ...

Continuous expansion tube

Torque shoulder of special screwed nipple for oil tubes and sleeves

The invention relates to a torque shoulder of a special screwed nipple for oil tubes and sleeves. An external thread reverse shoulder inclined plane inclines towards the inner part of a tube on the external thread end part of a tubular nipple connecting thread and on the position behind an internal thread tool withdrawal groove meshed with the external thread end part, the external thread reverse shoulder inclined plane and the tube forms an radial included angle of 15-20 degrees, and the external thread reverse shoulder inclined plane has the radial height of 1.5-2mm; the vertical plane of a triangular shoulder forms a 90-degree included angle with the center line of the oil tube and the sleeve; the reverse shoulder inclined plane is connected with a sealing face connected with a chamfer angle, and the chamfer angle is connected with the connecting thread; an internal thread reverse shoulder and the triangular shoulder are positioned on a position in contact with the end face of the external ...

Expansion sleeve joint with double hook shaped thread connection

The invention relates to an expansion sleeve joint with double hook shaped thread connection for the connection of integral joint expansion sleeves in oil and gas well engineering. Two-end structures of a male thread joint and a female thread joint correspondingly form sealed cabins, the sealed cabins are sealed by two fastened and inversely fastened bowl shaped rubber obturating rings, the deflection angle of a first hook surface of a hook shaped contact surface correspondingly formed by a single hook shaped thread of the male thread joint and a single hook shaped thread groove of the femalethread joint is 15 DEG, the deflection angle of a second hook surface is 28 DEG, the height of the second hook surface is 25 to 30 percent of that of the thread, the rounding radius between the firsthook surface and the second hook surface is 0.5 mm, the deflection angle of the reverse side of the thread is 5 DEG, the conicity of the thread is 1:23-1:25, and a hook tip of a second hook of the thread ...

Method for preparing polyphase structure drill rod materials

The invention relates to a method for preparing polyphase structure drill rod materials, which comprises the following compositions by mass percentage: 0.25 to 0.30 percent of carbon, less than 0.008 percent of sulfur, less than 0.010 percent of phosphorus, 0.5 to 1.0 percent of chromium, 0.6 to 1.2 percent of molybdenum, 0.10 to 0.15 percent of vanadium, 0.10 to 0.15 percent of niobium, 0.25 to 0.5 percent of lanthanum, and other elements and S135 steel grade drill rod elements. The heat treatment process comprises the following steps: firstly, performing vacuum melting and casting forming onvarious compositions, and treating the obtained product for 30 to 60 minutes at the temperature of between 925 and 935 DEG C after the obtained product is subjected to the production procedures of rolling and drilling of general drill rods; and secondly, cooling the obtained product to the temperature of between 280 and 420 DEG C, performing salt-bath quenching on the obtained product for 10 to 15 ...

Alloy pipe containing 18-24% of Mn and manufacturing method thereof

The present invention relates to an alloy pipe containing 18-24% of Mn and a manufacturing method thereof. The alloy pipe comprises the following components by mass percent: 0.002-0.2% of C, 18-24% of Mn, 0-4% of Si, 0-5% of Al, no more than 0.015% of P, no more than 0.01% of S, no more than 0.008% of N, or one or more of 1-6% of Cr, 0.1-0.5% of Cu, 0.01-0.6% of Nb, 0.01-0.1% of Ti and 0.01-0.3% of V, and balance of Fe. The manufacturing method comprises the following steps: casting the raw materials by vacuum melting, carrying out homogenizing annealing and hot-rolling on the cast materials so as to be manufactured into steel plates or bars; carrying out resistance-welding or hot-rolling on the steel plates or balls so as to be manufactured into pipe blanks; carrying out solid solution treatment and ageing treatment on the pipe blanks, wherein the obtained product has a uniform elongation percentage no less than 50% and a yield strength of 300-400MPa; and carrying out plastic deformation ...

Double-seam submerged-arc welding pipe with petroleum and natural-gas transfer and its production

Preparation method of continuous expansion pipe with high strength and high plastic elasticity

The invention relates to a preparation method of a continuous expansion pipe with high strength and high plastic elasticity, comprising the following components by weight: 0.03-0.12% of C, 0.17-0.40% of Si, 0.80-1.90% of Mn, not more than 0.010% of P, not more than 0.005% of S, 0-1.0% of Cr, 0.10-0.50% of Mo, 0-0.30% of Ni, 0-0.05% of V, 0-0.03% of Ti, 0-0.30% of Cu, 0.01-0.06% of Nb, and the reset being Fe. The method comprises the following steps: melting all components via an oxygen blowing converter, precisely melting outside the converter, degassing in vacuum, continuously casting, roughly rolling and precisely rolling so as to obtain a hot rolling plate coil, shearing into steel strips, welding oppositely, connecting the steel strips, and using the steel strip to produce a direct gap resistor weld steel pipe. The lowest yield strength is 485-760MPa; the lowest extension ratio is 25-35%; and the impact power is not less than 40J.

Alloy tube containing 13 to 19 percent of manganese and preparation method thereof

The invention relates to an alloy tube containing 13 to 19 percent of manganese and a preparation method thereof. The preparation method comprises the following steps that: 0.01 to 0.3 percent of C, 13 to 19 percent of Mn, 1 to 5 percent of Si, 0 to 5 percent of Al, less than or equal to 0.015 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.008 percent of N and the balance of Fe are added; or one or more of 1 to 6 percent of Cr, 0.1 to 0.5 percent of Cu, 0.01 to 0.15 percent of Nb, 0.01 to 0.1 percent of Ti and 0.01 to 0.15 percent of V are added on the basis of the above components are added; the above components are vacuum smelted, cast, homogeneously annealed and hot rolled to prepare a steel plate or a rod stock; the steel plate or the rod stock is made into a tube blank through resistance welding or hot rolling; and after the solution treatment and the aging treatment, an expandable tube is obtained; the homogenous extension rate is more than or equal ...

Expansion sleeve joint with double hook shaped thread connection

The invention relates to an expansion sleeve joint with double hook shaped thread connection for the connection of integral joint expansion sleeves in oil and gas well engineering. Two-end structures of a male thread joint and a female thread joint correspondingly form sealed cabins, the sealed cabins are sealed by two fastened and inversely fastened bowl shaped rubber obturating rings, the deflection angle of a first hook surface of a hook shaped contact surface correspondingly formed by a single hook shaped thread of the male thread joint and a single hook shaped thread groove of the female thread joint is 15 DEG, the deflection angle of a second hook surface is 28 DEG, the height of the second hook surface is 25 to 30 percent of that of the thread, the rounding radius between the first hook surface and the second hook surface is 0.5 mm, the deflection angle of the reverse side of the thread is 5 DEG, the conicity of the thread is 1:23-1:25, and a hook tip of a second hook of the thread ...

Combined loading expansion test device for entity expansion pipe

The invention relates to a combined loading expansion test device for an entity expansion pipe, comprising a loading frame, an expansion test system, an expansion clamping system and a sensor system, wherein the expansion test system is fixed on the loading frame, and one side of the loading frame is provided with the expansion clamping system. The invention has simple and reliable structure, can supply axial controllable mechanical tensile load of 0-2000kN and hydraulic pressure of 0-80Mpa, can realize the mechanical tensile expansion or hydraulic expansion or mechanical tensile and hydraulic pressure composite expansion test for the entity expansion whole pipe, can measure the displacement, the tensile load and the hydraulic pressure in an expansion test process and the radial deformation data of the entity expansion pipe in real time, can satisfy the expansion test of various sizes of entity expansion whole pipes or entity expansion pipe connecting structures, effectively avoids horizontal ...

Crack initiation steel pipe for full-scale gas bursting test of large-diameter high-grade steel gas pipeline and preparation method thereof

The invention discloses a crack initiation steel pipe for a full-scale gas bursting test of a large-diameter high-grade steel gas pipeline and a preparation method thereof, belonging to the field of a petroleum pipeline breakage control test. The steel pipe comprises the following components by weight percent: 0.07%-0.12% of C, 1.50%-1.75% of Mn, 0.15%-0.35% of Si, less than or equal to 0.015% of P, 0.010%-0.020% of S, 0.005%-0.030% of Al, less than or equal to 0.002% of O, less than or equal to 0.00015% of H, less than or equal to 0.005% of N and the balance of Fe; and carbon equivalent is less than or equal to 0.55%, and the cold cracking sensitive coefficient is less than or equal to 0.28%. The preparation method comprises the following steps: smelting and continuously casting the raw materials so as to form a thick slab; carrying out rough rolling and precise rolling so as to obtain a hot rolled steel plate; and forming the hot rolled steel plate, then welding, and then expanding diameter ...

Method for manufacturing high steel grade sulfur resistant drill pipe by laser cladding

The invention relates to a method for manufacturing a high steel grade sulfur-resistant drill pipe by laser cladding. In the method, in the condition of inert gas insulating air, nickel-base alloy anti-corrosion material is clad on the inner and outer pipe walls of an S135 steel grade drill pipe with conventional properties by laser, a nickel-base alloy anti-corrosion layer is clad on the non-thread area of a joint, threads are processed on the thread conical surface of the joint after a nickel-base alloy anti-corrosion layer is clad on the thread conical surface of the joint, and the end part of a pipe body is oppositely connected with the joint through friction welding; the output power of the laser is 3.5-4.5kW; laser beam spot size is not more than Phi 3mm; defocusing amount is 25-35mm; laser beam scanning line speed is 6.5-7.5mm/s; the inclined angle between the laser beam and the long axis direction of the pipe body is 40-50 degree; and the delivery rate of cladding wire material ...

High-grade large-strain pipeline steel and manufacturing method of steel pipe

The invention relates to a high-grade large-strain pipeline steel and a manufacturing method of a steel pipe. The high-grade large-strain pipeline steel comprises the following components in percentage by mass: 0.04-0.08 percent of C, 1.50-1.90 percent of Mn, 0.15-0.30 percent of Si, not more than 0.010 percent of P, not more than 0.003 percent of S, 0.005-0.03 percent of Al, 0.002-0.005 percent of Ca, not more than 0.005 percent of N, and the balance of Fe, wherein the carbon equivalent is not more than 0.55 percent and cold cracking sensitivity coefficient is not more than 0.25. The manufacturing method comprises the following steps of: carrying out smelting, Ca treatment, refining and degassing on the pipeline steel; carrying out continuous casting on the pipeline steel to form a thick plate blank; carrying out finish rolling on the thick plate blank; tempering at low temperature to prepare a hot rolling steel plate; moulding and welding the steel plate; and expanding to manufacture ...

Oil and bushing low-temperature powder embedding aluminizing agent for petroleum

The low temperature quick aluminizing agent specially for petroleum pipe and casing consists of metal source, activator, catalyst and stuffing. The metal source consists of 150-mesh Al powder in 10-20 wt% of the aluminizing agent, 120-mesh Zn powder in 10-25 wt%, 150-mesh Zn-Fe alloy powder in 10-20 wt% and/or 150-mesh Fe-Al alloy powder in 10-15 wt%. The activator consists of ammonium chloride, aluminum chloride, sodium fluoride and/or potassium bifluoride. The catalyst consists of 100-mesh Mo powder in 0-3 wt% and La and Os 0-3 wt%, with La and Os in the weight ratio of 1 to 1. The stuffing is 100-mesh alumina powder. The aluminizing agent is applied at 380-500 deg.c to obtain aluminized layer.

Method for manufacturing step-variable cold bending pipe

The invention relates to a method for manufacturing a step-variable cold bending pipe, comprising the following steps: (1) adopting a vertical hydraulic pressure cold bending machine to determine a bending angle in a unit step which can not cause overproof steel pipe deformation via a simulation test specific to the steel pipe used in a project, and defining the angle as a; (2) determining the bending angel b required to be realized by the cold bending pipe according to the line pipe design requirement, thus obtaining the required bending times which can be calculated as the formula: n=b/a; (3) measuring the length of the steel pipe to be bended, and determining the effective steel pipe length L1 in bending processing, thus calculating the selectable step L=L1/n for bending the steel pipe; and (4) bending based on that the step is L and the bending angle in the unit step is a, thus realizing manufacturing of the cold bending pipe. The method in the invention can manufacture cold bending ...

Pipeline steel Charpy specimen fracture separation degree grading method

The invention relates to a pipeline steel Charpy specimen fracture separation degree grading method, which comprises the following steps of: (1) for a specimen having fracture separation in a Charpy test, measuring the lengths of separation cracks on specimen fractures, and endowing the cracks with different scores m according to the lengths of the separation cracks; (2) sorting according to the lengths of cracks on the fractures, and endowing the differently sorted fracture separation cracks with different weight coefficients k; (3) adding each product of a scores mi of each fracture separation crack on the specimen fracture and a weight coefficient ki to obtain a total sore M of the fracture separation of the specimen; and (4) dividing the fracture separation degree into four grades, namely I grade, II grade, III grade and IV grade according to the total score M. If the specimen fracture separation coefficient exceeds a certain grade, a series temperature impact toughness test is carried ...

Selection method of test sample for steel pipe transverse yield strength test

The invention discloses a selection method of a test sample for a steel pipe transverse yield strength test, which overcomes the problem of that puzzlement is caused to the inspection and the judgment in practical engineering due to different test results by selecting different test samples existing in the pipeline design process at present, and meanwhile, the influence of residual stress on steel pipe strength, i.e. bearing capacity is taken into comprehensive consideration in the sample selecting process so as to ensure that the selection of a steel pipe yield strength test sample is more reasonable and economical. The invention adopts the technical scheme that a test sample is determined and selected through the ratio relation among the hydrostatic pressure circumferential yield strength sigmahs of a steel pipe to be tested, the tested yield strength sigmabs of a round bar sample and the tested yield strength sigmass of a platy sample; when the sigmahs is not less than 1.16sigmabs, the ...

Method for preparing X90 steel-grade bent pipes and pipe fittings

The invention relates to a method for preparing X90 steel-grade bent pipes and pipe fittings. The steel for making the bent pipes and pipe fittings comprises the following components in percentage by mass: 0.11 to 0.25 percent of C, 1.35 to 2percent of Mn, 0.3 to 0.5 percent of Si, no more than 0.010 percent of P, no more than 0.005 percent of S, 0.01 to 0.05 percent of Al, 0.002 to 0.005 percent of Ca, no more than 0.008 percent of N, and the balance of Fe, wherein elements Nb, Ti, V, Mo, Ni and Cr can also be added. The method comprises the steps that: hot rolled steel plates are obtained by smelting, rolling and air-cooling; hot rolled steel plates are prepared into longitudinal submerged arc welding pipes by forming and longitudinal submerged arc welding; the longitudinal submerged arc welding pipes undergo induction heating and thermal treatment to form bent pipes or under to a plurality of thermo mechanical forming processes to form pipe fittings. The bent pipes and pipe fittings ...

Method for computing spiral seam submerged-arc welding pipe residual stress

24-30% Mn-containing alloy pipe material and manufacture method thereof

The invention relates to a 24-30% Mn-containing alloy pipe material and a manufacture method thereof. The pipe material comprises the following components of: 0.001-0.35% of C, 24-30% of Mn, 0-5% of Si, 1.0-3.5% of Al, P which is less than and equal to 0.015%, S which is less than and equal to 0.010%, and Fe in balance amount, or one or two of 1-6% of Cr, 0.1-0.5% of Cu, 0.01-0.9% of Nb, 0.01-0.1% of Ti and 0.01-0.3% of V. The manufacture method comprises the following steps of: vacuum smelting and casting, annealing in a homogenizing way, hot rolling to obtain a steel plate or a bar material, electric resistance welding or hot rolling to obtain a pipe blank, and performing solid solution and aging treatment to obtain the alloy pipe material with good expansibility performance. The even elongation coefficient is more than or equal to 60%, and the yield strength is 250-400MPa. After performing 30-40% of plastic deformation, the even elongation coefficient is more than or equal to 25%, and ...

Continuous expansion tube

The invention relates to a continual bulged tube, and is used for the petroleum well cementation, or the treatment of the complicated accidents underground, and the well maintenance. The invention is characterized in that the chemical composition of the continual bulged tube material is that C is 0.08 percent to 0.14 percent; Si is 0.30 percent to 0.50 percent; Mn is 0.70 percent to 0.90 percent; P is less than or equal to 0.025 percent; S is less than or equal to 0.005 percent; Cr is 0.57 percent to 0.70 percent; Mo is less than or equal to 0.2 percent; Ni is 0.13 percent to 0.20 percent; V is 0.002 percent to 0.010 percent; Ti is 0.005 percent to 0.010 percent; Cu is 0.20 percent to 0.25 percent; Nb is 0.005 percent to 0.010 percent; Fe is the surplus quantity. The manufacture process comprises a longitudinal-seam electric resistance welding (ERW) tube is adopted; the welding seal burrs inside and outside the continual bulged tube are removed; heat treatment is performed for the entire ...

High-grade large-strain pipeline steel and manufacturing method of steel pipe

The invention relates to a high-grade large-strain pipeline steel and a manufacturing method of a steel pipe. The high-grade large-strain pipeline steel comprises the following components in percentage by mass: 0.04-0.08 percent of C, 1.50-1.90 percent of Mn, 0.15-0.30 percent of Si, not more than 0.010 percent of P, not more than 0.003 percent of S, 0.005-0.03 percent of Al, 0.002-0.005 percent of Ca, not more than 0.005 percent of N, and the balance of Fe, wherein the carbon equivalent is not more than 0.55 percent and cold cracking sensitivity coefficient is not more than 0.25. The manufacturing method comprises the following steps of: carrying out smelting, Ca treatment, refining and degassing on the pipeline steel; carrying out continuous casting on the pipeline steel to form a thick plate blank; carrying out finish rolling on the thick plate blank; tempering at low temperature to prepare a hot rolling steel plate; moulding and welding the steel plate; and expanding to manufacture ...

Manufacturing method of expandable casing for oil and gas well

The invention relates to a steel used for a solid expandable casing of an oil and gas well and a manufacturing method of the expandable casing, which are applied to prepare the expandable casing of the oil and gas well in oil and gas industry. The steel alloy material used for the solid expandable casing of the oil and gas well comprises the following components in percentage by mass: 0.1-0.3% of C, 1.5-3.5% of Mn, 1-2.5% of Si, 0.1-3% of Al, less than or equal to 0.010% of P, less than or equal to 0.005 % of S, 0.003-0.010% of Ca, less than or equal to 0.0007% of N and the balance of Fe. The preparation method comprises the steps of vacuum melting, continuous casting and homogenizing annealing; hot rolled plate coils are prepared via controlling rolling and cooling, and the hot rolled plate coils are used for producing straight seam resistance welded steel pipes; and expandable pipe materials can be obtained via two stages of isothermal heat treatment. Threads are processed at both ends ...

Single-hook screw thread and end plane metal self-sealing expansion sleeve pipe

Disclosed is an expansion casing with single hook shape screw thread and end surface metal self-sealing, which is an expansion casing applied to petroleum oil gas well engineering. The expansion casing is characterized in that the external thread and the internal thread are provided with single hook shape screw threads, and the single hook shape screw threads match with each other to form thread hook surface metal sealing. The top of the external thread and the root of the internal thread are provided with cylindrical metal sealing surfaces, and the metal sealing surfaces match with each other to form cylindrical metal sealing. the cylindrical metal sealing surface of the internal thread is provided with an annular sealing groove and a rubber sealing ring which plays the sealing function. The expansion casing has the effects that the external thread and the internal thread has negative angle hook shape internal and external threads which are tightly engaged and even contact stress distribution ...

Production method of X70 steel grade elbow pipes and pipe fittings

The invention relates to a production method of X70 steel grade elbow pipes and pipe fittings. The steel used for producing the elbow pipes and pipe fittings comprises the following components by mass percent: 0.09-0.15% of C, 1.25-1.75% of Mn, 0.2-0.4% of Si, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.01-0.04% of Al, 0.002-0.005% of Ca, less than or equal to 0.008% of N and the balance of Fe. The production method comprises the following steps: melting the materials, rolling under control, and air cooling to obtain a hot-rolled sheet steel; performing molding and longitudinally-submerged arc welding to obtain longitudinally-submerged arc welded steel pipes; and performing induction heating, annealing, and p heat treatment to obtain elbow pipes, or performing thermo-mechanical molding many times to obtain pipe fittings. The elbow pipes and pipe fittings produced with the production method provided by the invention have high strength, good low temperature toughness ...

Manufacturing method of high-strength and high-plasticity continuous tube

The invention relates to a manufacturing method of a high-strength and high-plasticity continuous tube. The continuous tube comprises the following chemical components in mass percentage: 0.05-0.12% of C, 0.17-0.37% of Si, 0.60-1.75% of Mn, not more than 0.010% of P, not more than 0.005% of S, 0.20-1.0% of Cr, 0.15-0.45% of Mo, 0.10-0.35% of Ni, 0-0.05% of V, 0-0.03% of Ti, 0.10-0.25% of Cu, 0-0.07% of Nb, 0.02-0.04% of Al, 0.002-0.004% of Ca and the balance of Fe. The manufacturing method comprises the following steps: manufacturing hot-rolled steel coils; longitudinally shearing and butt-welding the steel coils; and producing a straight seam electric-resistance-welded steel tube by using steel bands and welding to obtain welding seams by normalization at the temperature of 930-960 DEG C. Yield strength of the continuous tube reaches 490-800MPa and elongation percentage thereof reaches 28-40%.

24-30% Mn-containing alloy pipe material and manufacture method thereof

The invention relates to a 24-30% Mn-containing alloy pipe material and a manufacture method thereof. The pipe material comprises the following components of: 0.001-0.35% of C, 24-30% of Mn, 0-5% of Si, 1.0-3.5% of Al, P which is less than and equal to 0.015%, S which is less than and equal to 0.010%, and Fe in balance amount, or one or two of 1-6% of Cr, 0.1-0.5% of Cu, 0.01-0.9% of Nb, 0.01-0.1% of Ti and 0.01-0.3% of V. The manufacture method comprises the following steps of: vacuum smelting and casting, annealing in a homogenizing way, hot rolling to obtain a steel plate or a bar material, electric resistance welding or hot rolling to obtain a pipe blank, and performing solid solution and aging treatment to obtain the alloy pipe material with good expansibility performance. The even elongation coefficient is more than or equal to 60%, and the yield strength is 250-400MPa. After performing 30-40% of plastic deformation, the even elongation coefficient is more than or equal to 25%, and ...

Manufacturing method of high-strength and high-plasticity continuous tube

The invention relates to a manufacturing method of a high-strength and high-plasticity continuous tube. The continuous tube comprises the following chemical components in mass percentage: 0.05-0.12% of C, 0.17-0.37% of Si, 0.60-1.75% of Mn, not more than 0.010% of P, not more than 0.005% of S, 0.20-1.0% of Cr, 0.15-0.45% of Mo, 0.10-0.35% of Ni, 0-0.05% of V, 0-0.03% of Ti, 0.10-0.25% of Cu, 0-0.07% of Nb, 0.02-0.04% of Al, 0.002-0.004% of Ca and the balance of Fe. The manufacturing method comprises the following steps: manufacturing hot-rolled steel coils; longitudinally shearing and butt-welding the steel coils; and producing a straight seam electric-resistance-welded steel tube by using steel bands and welding to obtain welding seams by normalization at the temperature of 930-960 DEG C. Yield strength of the continuous tube reaches 490-800MPa and elongation percentage thereof reaches 28-40%.