Production method for non-annealed medium carbon cold heading steel hot-rolled wire rod

The invention discloses a production method for a non-annealed medium carbon cold heading steel hot-rolled wire rod. The production method includes steps that (1) smelting molten steel, and continuously casting to form a billet; (2) slowly cooling the billet to release stress; (3) heating the slowly cooled hot-rolled billet to 1150 to 1190 degrees centigrade, preserving the heat for 110 to 140 minutes, and dephosphorizing through high pressure water; (4) carrying out rough intermediate rolling, pre-precision rolling and finish rolling on the dephosphorized hot-rolled billet, wherein the finish rolling temperature is 965 to 995 degrees centigrade, the coiling temperature is controlled at 960 to 980 degrees centigrade after finishing finish rolling, and the dimensional precision is performed with negative common difference; (5) feeding a hot-rolled steel wire rod to a cooling line, closing a fan and a heat holding cover, and keeping the steel wire rod in the heat holding cover for at least ...

Bloom continuous casting dynamic soft reduction process for high-quality tire cord steel

The invention relates to a bloom continuous casting dynamic soft reduction process for high-quality tire cord steel, belonging to the technical field of metallurgy continuous casting and used for solving the problems of internal quality defects of casting billets such as central segregation, central porosity, central contraction cavity and the like which are easy to occur in tire cord steel bloomcontinuous casting. The invention adopts the technical scheme that in a continuous casting soft reduction region, the reduction amount is controlled by the variation of casting billet central solid phase rate fs, and a quantitative relationship of the reduction amount of a soft reduction stand and the casting billet central solid phase rate is given. By adopting the dynamically controlled soft reduction process, the central segregation of tire cord steel casting billets can be remarkably lightened with the casting billets center carbon segregation index controlled between 0.96 to 1.05 and theaverage ...

Ultrahigh-strength prestressed steel wire rod and production method thereof

The invention relates to an ultrahigh-strength prestressed steel wire rod. The ultrahigh-strength prestressed steel wire rod comprises the following chemical components in percentage by mass: 0.92 to 1.03 percent of C, 0.50 to 0.90 percent of Mn, 0.30 to 0.90 percent of Si, 0.20 to 0.40 percent of Cr, 0.03 to 0.07 percent of V and the balance of Fe and inevitable impurities. The production process of the wire rod comprises the steps of converter smelting, LF furnace refining, bloom continuous casting, bloom heating, cogging, billet heating, controlled rolling and controlled cooling. The tensile strength of the steel wire rod reaches 1400 MPa or above, the requirement of 2230 MPa grade steel strands is met, the sorbite rate in the steel wire rod reaches 90% or above, the thickness of a sorbite lamella is 70-100 nanometers, and the steel wire rod is uniform in structure and free of martensite abnormal structures.

One-step production method for high-manganese and high-nitrogen corrosion-resistant steel G6811

The invention discloses a one-step production method for high-manganese and high-nitrogen corrosion-resistant steel G6811. The one-step production method comprises a molten iron pretreatment process, an AOD furnace process, an LF furnace process and a continuous casting machine process, wherein the AOD furnace process comprises six decarburization periods, an oxygen blowing and heating reduction period and a desulphurization period, the six decarburization periods are determined according to the upper control limit of carbon content, and the upper limits of carbon contents from the first decarburization period to the sixth decarburization period are respectively 1.50%, 0.40%, 0.25%, 0.15%, 0.10% and 0.05%. According to the method, the high-alloy corrosion-resistant steel G6811 produced by using a one-step method that dephosphorized molten iron is directly added into an AOD furnace is achieved through controlling the gas scale models, feeding occasions, feeding speeds and temperatures at ...

Method for controlling oxygen and reducing nitrogen in molten steel

Spheroidized annealing process for shortening annealing cycle of hot rolled wire rods

The invention relates to a spheroidized annealing process for shortening the annealing cycle of hot rolled wire rods, belongs to the technical field of metal wire annealing process. The technical scheme of the spheroidized annealing process lies in that firstly, lamellar pearlites are heated to 770-790 DEG C, heat preservation is carried out for a certain time to enable the lamellar pearlite to be fused quickly, so that the undissolved carbide particles can promote the transformation of austenite into the spheroidized microscopic structure; the temperature is lowered to 710-730 DEG C, heat preservation is performed for 4-6 hours to enable the fused cementite to gather spherically, and along with the time extension of heat preservation, the rate of spheroidization of the cementite is gradually improved, and the uniformity is gradually improved. A slow three-stage cooling manner is adopted, so that the uniformity of the spheroidized structure is improved. According to the spheroidized annealing ...

Production method for improving mechanical property uniformity of chromium-molybdenum steel wire rod

The invention discloses a production method for improving mechanical property uniformity of a chromium-molybdenum steel wire rod, and belongs to the technical field of steel wire rod production. Comprising the steps of smelting, continuous casting, rolling and cooling. A casting blank comprises the following chemical components in percentage by weight: 0.35 to 0.37 percent of C, 0.15 to 0.30 percent of Si, 0.70 to 0.80 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.020 percent of S, 0.95 to 1.05 percent of Cr, 0.15 to 0.25 percent of Mo and the balance of iron and inevitable impurities. The first three heat preservation covers are opened after spinning, the roller way speed of the first section is 0.12 m/s, and the roller way speed of the tail section is 0.35 m/s; according to the invention, the hot-rolled wire rod with uniform mechanical properties is obtained through component control, controlled rolling and controlled cooling technologies.

Production method for improving hot charging rate of bloom low-carbon aluminum killed steel billet

The invention discloses a production method for improving the hot charging rate of a bloom low-carbon aluminum killed steel billet, and belongs to the technical field of metallurgy. The production method comprises the procedures of molten iron desulfurization, converter treatment, LF furnace treatment, RH furnace treatment, continuous casting, cogging and rolling. A continuous casting procedure: the surface temperature of a casting blank after three times of cooling is less than or equal to 300 DEG C, and the temperature after surface temperature return before hot charging is less than or equal to 600 DEG C; the surface temperature of the steel billet before entering the furnace is greater than or equal to 450 DEG C; on the premise that the product quality is guaranteed, hot charging is carried out on the steel billets, pile cooling treatment is not needed any more, the purposes of saving energy, reducing consumption and improving the yield are achieved, meanwhile, the product surface quality ...

high-strength steel wire rod with good low temperature impact toughness and production method thereof

The invention discloses a high-strength steel wire rod with good low temperature impact toughness and a production method of the high-strength steel wire rod. The high-strength steel wire rod contains the following steel type components by weight percent: 0.30%-0.50% of C, 0.10%-0.40% of Si, 0.70%-1.00% of Mn, less than or equal to 0.020% of P, less than or equal to 0.020% of S, 0.70%-1.20% of Cr, 0.10 %-0.30% of Mo, and the balance of Fe and trace impurities. The high-strength steel wire rod contains small and uniform in crystalline grains, and is low in ductile-brittle transition temperature, and has high material strength and toughness. The high-strength steel wire rod is free of other precious metals, is low in heat treatment cost, and has the characteristics of low production cost and low using cost. The method controls the austenitizing degree and phase change temperature by adjusting the temperatures of heating, finish rolling and spinning, as well as cooling speed, and the low temperature ...

Method for improving surface quality of wire rod for piston rod of automobile shock absorber

The invention discloses a method for improving the surface quality of a wire rod for a piston rod of an automobile shock absorber. The method comprises the working procedures of spinning, coiling and packaging. The specification of the wire rod for the piston rod of the automobile shock absorber is phi 12-20 mm, and the spinning parameters are as follows: the amplitude is 2.5-5.5%, the period is 3-6 s, and the advance coefficient is 1-2.5%. By optimizing spinning process parameters and a coil collecting mode and reducing packaging pressure, coil discharging quality and coil rod packaging quality are improved, the defects of surface scratches of coil rods, pits of finished piston rods and pocking marks are reduced, the reject ratio of products is reduced to be smaller than or equal to 3% from 11%, the yield of the products is increased, and customer losses are reduced.

GCr15 bearing steel bloom continuous casting dynamic soft reduction process

The invention relates to a GCr15 bearing steel bloom continuous casting dynamic soft reduction process, which belongs to the technical field of metallurgical continuous casting and is used for solvingthe problems that the GCr15 bearing steel bloom continuous casting is easy to cause central segregation, central looseness, central parosity and other casting slab internal quality defects. The technical scheme is as follows: the reduction of a continuous casting soft reduction region is controlled through the change of central solid phase rate fs of a casting slab, and the relationship between the reduction of a soft reduction rack and the central solid phase rate of the casting slab is given out. The adoption of the soft reduction process of dynamic control can significantly reduce the central segregation of the GCr15 bearing steel casting slab, the central carbon segregation index of the casting slab is 0.95-1.08, and the average central segregation is 1.03; the process can also obviously ...

GCr15 bearing steel bloom continuous casting dynamic soft reduction process

The invention relates to a GCr15 bearing steel bloom continuous casting dynamic soft reduction process, which belongs to the technical field of metallurgical continuous casting and is used for solving the problems that the GCr15 bearing steel bloom continuous casting is easy to cause central segregation, central looseness, central parosity and other casting slab internal quality defects. The technical scheme is as follows: the reduction of a continuous casting soft reduction region is controlled through the change of central solid phase rate fs of a casting slab, and the relationship between the reduction of a soft reduction rack and the central solid phase rate of the casting slab is given out. The adoption of the soft reduction process of dynamic control can significantly reduce the central segregation of the GCr15 bearing steel casting slab, the central carbon segregation index of the casting slab is 0.95-1.08, and the average central segregation is 1.03; the process can also obviously ...

Bloom continuous casting dynamic soft reduction process for high-quality tire cord steel

The invention relates to a bloom continuous casting dynamic soft reduction process for high-quality tire cord steel, belonging to the technical field of metallurgy continuous casting and used for solving the problems of internal quality defects of casting billets such as central segregation, central porosity, central contraction cavity and the like which are easy to occur in tire cord steel bloomcontinuous casting. The invention adopts the technical scheme that in a continuous casting soft reduction region, the reduction amount is controlled by the variation of casting billet central solid phase rate fs, and a quantitative relationship of the reduction amount of a soft reduction stand and the casting billet central solid phase rate is given. By adopting the dynamically controlled soft reduction process, the central segregation of tire cord steel casting billets can be remarkably lightened with the casting billets center carbon segregation index controlled between 0.96 to 1.05 and theaverage ...

Cold forging steel hot-rolled wire rod, production method thereof and method for preparing fine wire

The invention discloses a cold heading steel hot-rolled wire rod, a production method thereof and a method for preparing a fine wire, and belongs to the technical field of metallurgy. The steel comprises the following chemical components in percentage by mass: 0.16 to 0.23 percent of C, less than or equal to 0.30 percent of Si, 0.25 to 0.90 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.040 percent of Ti, 0.02 to 0.08 percent of Al, 0.0005 to 0.0050 percent of B and the balance of iron and inevitable impurities. The production method comprises the steps of heating, rolling and cooling hot-rolled steel billets. The obtained hot-rolled wire rod is low in strength and high in plasticity, the banded structure is smaller than or equal to grade 2, the grain size is larger than or equal to grade 9, and the ferrite content is larger than or equal to 83%. And the hot-rolled wire rod is subjected to acid pickling and phosphating ...