Steel for LPG fuel tank and welding method thereof

The invention discloses steel for an LPG (Liquefied Petroleum Gas) fuel tank and a welding method thereof. Belongs to the technical field of new material connection. The steel for the LPG fuel tank comprises the following main chemical components: C, Mn, Si, P, S, Al, Ti and the balance of Fe and incidental impurities. According to the invention, the welding joint form is butt joint, the welding position is flat welding, an I-shaped or Y-shaped groove is adopted, and the assembly gap is 0-1mm; according to the welding method, single-wire single-channel double-face submerged arc automatic welding is adopted, the thickness specification of the steel for the LPG fuel tank of 8-30 mm is covered, the welding method is used for welding the steel for the LPG fuel tank, and the actual performance result of a welded joint is good.

Economical niobium-free 690Pa-grade quenched and tempered high-strength steel plate and manufacturing method thereof

The invention discloses an economical niobium-free 690Pa-level quenched and tempered high-strength steel plate and a manufacturing method thereof. Belongs to the technical field of steel production. The steel comprises the following chemical components: C, Si, Mn, P, S, Ti, V, Cr, Mo, Alt, B and the balance of Fe and impurities. The method comprises the following steps: a smelting process, a continuous casting process, a heating process, a rolling and tempering process and the like. The invention provides an economical 690MPa high-strength steel plate with excellent comprehensive performance and a production method thereof. Batten bainite and granular bainite are obtained, and the structure is uniform and fine; the structure of lath bainite and granular bainite is beneficial to keeping strength and excellent plasticity and toughness.

Roll gap lubricating method for producing ultrathin hot rolling strip steel with semi-endless rolling technology

The invention discloses a roll gap lubricating method for producing ultrathin hot rolling strip steel with a semi-endless rolling technology. The opening of an electromagnetic control valve is controlled so that 50-100 ml of lubricating oil flows through an oil supply pipe and enters an oil-water mixer every minute; the opening of a water quantity regulation control valve is controlled so that 40-60 L of circulating water flows through a water supply pipe and enters the oil-water mixer every minute; and the oil-water mixture in the oil-water mixer is injected to the roll surfaces of an upper working roll and a lower working roll through a nozzle on a spraying header respectively. The first rolling mill and the seventh rolling mill are not lubricated in the hot rolling process of strip steel, and the head and tail of the strip steel are not lubricated. When the head of the strip steel reaches the next rolling mill, the electromagnetic control valve on the previous rolling mill is opened; ...

Quenched and tempered steel plate for hydrogen-resistant pressure vessel and production process of quenched and tempered steel plate

The invention discloses a quenched and tempered steel plate for a hydrogen-resistant pressure vessel and a production process of the quenched and tempered steel plate. The steel plate comprises the following chemical components in percentage by mass: less than or equal to 0.15% of C, 0.15 to 0.35% of Si, 0.60 to 1.60% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, less than or equal to 0.50% of Cu, 0.70 to 1.50% of Ni, 0.25 to 0.80% of Cr, 0.25 to 0.80% of Mo, 0.03 to 0.08% of V, less than or equal to 0.030% of Ti, 0.03 to 0.05% of Als, less than or equal to 0.0030% of B and the balance of Fe and other inevitable impurities. The thickness of the steel plate is 72 mm. The production process of off-line quenching and high-temperature tempering ensures the high strength and toughness of the steel plate. The lower yield strength Rp0.2 of the steel plate is larger than or equal to 690 MPa, the tensile strength Rm is 800-900 MPa, the ductility A is larger than or ...

Manufacturing method of marine atmosphere corrosion-resistant structural 345MPa-grade steel plate

The invention discloses a marine atmosphere corrosion-resistant structural 345MPa-grade steel plate and a preparation method thereof. Belongs to the technical field of steel production. The steel comprises the following chemical components: C, Si, Mn, P, S, Nb, Ti, V, Cu, N, Mo, Alt and the balance of Fe and inevitable inclusions. The method comprises the following steps of smelting, continuous casting, soaking, rolling, relaxation, cooling and off-line tempering. Through scientific component design and a matched manufacturing method of controlled rolling, controlled cooling and tempering, the 345MPa-grade weather-proof bridge steel with the low yield ratio, high toughness and high ductility is obtained; the yield strength is 400 MPa or above, the tensile strength is 530 MPa or above, the yield ratio is smaller than or equal to 0.80, Akv at the temperature of-60 DEG C is 230 J or above, the ductility is larger than or equal to 24%, the corrosion-resistant alloy index V is larger than or ...

COMPOSITE ANTISEISMIC FIREPROOF BUILDING STEEL AND PREPARATION METHOD THEREOF

Method for producing high-strength steel with yield strength of 600MPa level

The invention belongs to the technical field of high-strength steel production, and relates to a method for producing high-strength steel with yield strength of 600MPa level. The high-strength steel is smelted by a converter or an electric furnace; and after the molten steel components are qualified, the molten steel components are delivered to an LF furnace to carry out refining for the molten steel and fine adjustment for the components, wherein the steel comprises the following components in percentage by mass: 0.03 to 0.08 percent of C, 0.20 to 0.50 percent of Si, 1.0 to 1.5 percent of Mn, 0.06 to 0.10 percent of Ti, 0.02 to 0.08 percent of Nb, 0.02 to 0.06 percent of Al, less than or equal to 0.008 percent of limited element S, less than or equal to 0.008 percent of N, less than or equal to 0.04 percent of P, and the balance of Fe. The method adopts a thin slab blank to continuously cast the steel, the charging temperature of a casting blank is between 950 and 1,050 DEG C, the heating ...

Method for producing hot rolling strip steel of 0.6-0.8mm

The invention discloses a method for producing hot rolling strip steel of 0.6-0.8mm by adopting an advanced semi-endless rolling technology. The method comprises the following steps of: delivering qualified converter molten steel into a ladle furnace for refining, casting the molten steel into a continuous casting blank with a length of 60-240m, a thickness of 50-60mm and a width of 1,000-1,350mmat a continuous casting drawing speed of 3.5-6.0m/min; directly delivering the continuous casting blank into a roller hearth type soaking pit furnace at 1,100-1,180 DEG C, wherein the soaking time ofthe tail part of the continuous casting blank is longer than 15min; descaling the soaked continuous casting blank and then delivering the continuous casting blank into a fine continuous rolling machine set to carry out multi-segmentation rolling of dynamic specification changing matching or unmatched working roller gap lubrication, wherein the outlet thickness of a first roll F7 used for penetrating ...

Submerged-arc welding method of steel for LPG fuel tank

The invention discloses a submerged arc welding method of steel for an LPG fuel tank. Belongs to the technical field of new material connection. The steel for the LPG fuel tank comprises the following main chemical components: C, Mn, Si, P, S, Al, Ti and the balance of Fe and incidental impurities. According to the invention, the welding joint form is butt joint, the welding position is flat welding, a Y-shaped or X-shaped groove is adopted, and the assembly gap is 0-1mm; according to the welding method, single-wire multi-channel double-face submerged arc automatic welding is adopted, the specification of 21-30 mm thickness of the steel for the LPG fuel tank is covered, the welding method is used for welding the steel for the LPG fuel tank, and the actual performance result of a welded joint is good.

Method for producing high-strength steel with yield strength of 700MPa level

The invention relates to a method for producing high-strength steel with yield strength of 700MPa level, and belongs to the technical field of high-strength steel production. The high-strength steel comprises the following components in percentage by weight: 0.03 to 0.08 percent of C, 0.20 to 0.50 percent of Si, 1.4 to 2.0 percent of Mn, 0.10 to 0.15 percent of Ti, 0.02 to 0.08 percent of Nb, 0 to 0.3 percent of V, 0.02 to 0.06 percent of Al, less than or equal to 0.008 percent of limited element S, less than or equal to 0.008 percent of N, less than or equal to 0.04 percent of P, and the balance of Fe and inevitable impurity elements. The process adopts a thin slab blank to continuously cast the steel, the charging temperature of a casting blank is between 950 and 1,050 DEG C, the heating temperature is more than or equal to 1,150 DEG C, the discharging temperature is between 1,080 and 1,160 DEG C, the final rolling temperature is between 820 and 880 DEG C, and after laminar cooling, the ...

Method for producing low carbon bainite high-strength steel based on sheet bar continuous casting and rolling process flow

The invention discloses a method for producing high-strength low-carbon bainite steel based on thin slab continuous casting and rolling process. The method includes the following steps: melting by using a rotary furnace or an electric furnace, refining molten steel in an LF furnace after the component analysis, performing the composition adjustment, continuously casting thin slabs, directly heating the thin slabs at the temperature of 950-1100 DEG C in a roller-hearth heating (soaking) furnace at a temperature not less than 1150 DEG C, controlling the tapping temperature of heated thin slabs in a range from 1050 DEG C to1160 DEG C, rolling by using a continuous rolling mill to produce plates, finishing at a temperature of 840-860 DEG C, performing laminar cooling, and coiling with a down coiler at a temperature of 550-600 DEG C to produce the steel coil. The method can produce non-tempered high-strength steel based on thin slab continuous casting and rolling process, and has the advantages ...

Method for controlling head and tail temperature difference of semi-endless rolled overlong casting blank

The invention discloses a method for controlling the head and tail temperature difference of a semi-endless rolled overlong casting blank, which is used for solving the problem of poor longitudinal temperature uniformity of an overlong casting blank in a semi-endless rolling process. The invention has the technical scheme that the method comprises the following steps of: making the overlong casting blank enter a soaking pit at a fixed blank pulling speed V0 and making the overlong casting blank advance at a speed V1 not higher than V1max after the tail of the overlong casting blank passes through an accelerated point until the head of the casting blank arrives at the tail end of a heating section, wherein V1 is not less than V0 and not greater than V1max; then making the overlong casting blank advance to the tail end of a blank discharging section at a speed V2; and finally making the overlong casting blank enter a rolling mill at a speed V3 matched with a rolling mill F1 until that the ...

Converter production forecasting method based on big data

The invention discloses a converter production forecasting method based on big data, and the method comprises the following steps: data collection, data preprocessing, key variable recognition, model construction and model training and verified.The method comprises the following steps: taking converter raw material information, converter auxiliary material information, production process information, end point and tapping information as characteristic variables; according to the control requirements of the converter process, the correlation among the characteristic variables is identified through Pearson correlation analysis, the characteristic variables with medium correlation and strong correlation are reserved, the characteristic variables without correlation and weak correlation are removed, then training verification is carried out based on a DNN neural network model of a BP algorithm, and the converter production prediction accuracy is improved to be not smaller than 90%.

80-mm-Thick Low-Cost FH420 Marine Engineering Steel Plate and Manufacturing Method Thereof

Method for producing hot rolling strip steel of 0.6-0.8mm

The invention discloses a method for producing hot rolling strip steel of 0.6-0.8mm by adopting an advanced semi-endless rolling technology. The method comprises the following steps of: delivering qualified converter molten steel into a ladle furnace for refining, casting the molten steel into a continuous casting blank with a length of 60-240m, a thickness of 50-60mm and a width of 1,000-1,350mm at a continuous casting drawing speed of 3.5-6.0m/min; directly delivering the continuous casting blank into a roller hearth type soaking pit furnace at 1,100-1,180 DEG C, wherein the soaking time of the tail part of the continuous casting blank is longer than 15min; descaling the soaked continuous casting blank and then delivering the continuous casting blank into a fine continuous rolling machine set to carry out multi-segmentation rolling of dynamic specification changing matching or unmatched working roller gap lubrication, wherein the outlet thickness of a first roll F7 used for penetrating ...

Method for producing low carbon bainite high-strength steel based on sheet bar continuous casting and rolling process flow

The invention discloses a method for producing high-strength low-carbon bainite steel based on thin slab continuous casting and rolling process. The method includes the following steps: melting by using a rotary furnace or an electric furnace, refining molten steel in an LF furnace after the component analysis, performing the composition adjustment, continuously casting thin slabs, directly heating the thin slabs at the temperature of 950-1100 DEG C in a roller-hearth heating (soaking) furnace at a temperature not less than 1150 DEG C, controlling the tapping temperature of heated thin slabs in a range from 1050 DEG C to1160 DEG C, rolling by using a continuous rolling mill to produce plates, finishing at a temperature of 840-860 DEG C, performing laminar cooling, and coiling with a down coiler at a temperature of 550-600 DEG C to produce the steel coil. The method can produce non-tempered high-strength steel based on thin slab continuous casting and rolling process, and has the advantages ...

Method for controlling head and tail temperature difference of semi-endless rolled overlong casting blank

The invention discloses a method for controlling the head and tail temperature difference of a semi-endless rolled overlong casting blank, which is used for solving the problem of poor longitudinal temperature uniformity of an overlong casting blank in a semi-endless rolling process. The invention has the technical scheme that the method comprises the following steps of: making the overlong casting blank enter a soaking pit at a fixed blank pulling speed V0 and making the overlong casting blank advance at a speed V1 not higher than V1max after the tail of the overlong casting blank passes through an accelerated point until the head of the casting blank arrives at the tail end of a heating section, wherein V1 is not less than V0 and not greater than V1max; then making the overlong casting blank advance to the tail end of a blank discharging section at a speed V2; and finally making the overlong casting blank enter a rolling mill at a speed V3 matched with a rolling mill F1 until that the ...

Micro-molybdenum-type weathering bridge steel plate and preparation method thereof

A micro-molybdenum-type weathering bridge steel plate disclosed by the present invention is characterized in that the steel plate is smelted from the following components by weight: C: 0.05-0.08%, Si: 0.30-0.50%, Mn: 1.25-1.35%, P: 0.010-0.014%, S≤0.003%, Nb: 0.020-0.030%, Ti: 0.010-0.020%, V: 0.040-0.050%, Cu: 0.25-0.40%, Ni: 0.25-0.35%, Cr: 0.45-0.55%, Mo: 0.03-0.08%, Alt: 0.020-0.040%, and the balance from Fe and impurities. Less content of molybdenum reduces the production cost of the steel plate, the yield strength of the steel plate is 500-600 MPa, the yield strength ratio is ≤0.85, and the maximum thickness of the steel plate can reach 80 mm.

Large-thickness q960e ultra-high strength steel production method