1194 results about "Bainite" patented technology

Provided is a high-strength steel sheet having excellent member strength, ductility, stretch flangeability, bendability of a shear end surface, and low-temperature toughness. A high-strength steel sheet having a prescribed component composition and a steel structure in which the area ratio of martensite is 10%-80%, the area ratio of bainite is 2%-70%, the area ratio of ferrite is 80% or less, and the area ratio of retained austenite is 15% or less at a position at 1 / 4 of the sheet thickness. The ratio of the number of martensite blocks in which metastable carbides are present relative to the number of martensite blocks is 2% or more, and the standard deviation [sigma] n of the nano-hardness relative to the average value [Hn] ave of the nano-hardness is 0.60 x [Hn] ave or less when the nano-hardness at 225 points or more is measured at a position of 1 / 4 of the sheet thickness.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 1960MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After high-carbon components containing trace B are designed, rolled and spun into a wire rod, online molten salt rapid quenching treatment is carried out, and the wire rod is firstly subjected to front-section molten salt treatment, so that the wire rod is cooled at the cooling speed of greater than or equal to 36 DEG C / s and enters a bainite and pearlite mixed phase region from an austenite state; the method comprises the following steps: quenching a steel wire rod to form a structure mainly comprising quenched bainite and a sorbite structure, carrying out rear-section molten salt treatment on the steel wire rod, increasing the molten salt temperature, promoting isothermal tempering of the quenched bainite and the sorbite structure, and carrying out roller way slow cooling to prepare the hot-rolled steel wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered sorbite, tempered bainite and ferrite, the composition system can be simplified, the strength and plasticity matching and rapid production of the wire rod are considered, the tensile strength is 1330-1380 MPa, the percentage reduction of area is 35%-40%, and the wire breaking risk in the wire drawing and twisting process of the stranded wire steel can be reduced.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2100MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod, after a C-Si-Mn-Cr-Mo high-carbon component system is rolled and spun into a wire rod, the wire rod is subjected to online molten salt strong quenching isothermal treatment, so that the wire rod is firstly subjected to front-section molten salt treatment and is cooled at a cooling speed of greater than or equal to 33 DEG C / s, and enters a bainite phase region from an austenite state; the method comprises the following steps: firstly, carrying out first-stage molten salt treatment to promote transformation of austenite into bainite, then carrying out later-stage molten salt treatment to form a structure mainly comprising bainite, carrying out isothermal tempering on the structure, reserving part of untransformed retained austenite, and finally, carrying out roller way slow cooling to promote transformation of the untransformed retained austenite into martensite, and carrying out tempering, the microstructure of the hot-rolled wire rod comprises a complex-phase structure composed of tempered bainite and tempered martensite, the tensile strength of the hot-rolled wire rod can reach 1435-1485 MPa, the percentage reduction of area of the hot-rolled wire rod is 31%-36%, off-line heat treatment of follow-up machining is avoided, and the risk of wire breakage is reduced.

The invention discloses a wide and thick steel plate for a 700MPa-grade corrosion-resistant anti-fatigue marine tendon pipe and a production method of the wide and thick steel plate. According to the component design of the wide and thick steel plate, CEIIW is controlled to be 0.41-0.47%, CEPcm is controlled to be 0.16-0.20%, low-Nb and low-Mo design is adopted, the phase change temperature is increased, and phase change of polygonal ferrite is promoted; rE solid solution, interface segregation and other effects are fully utilized to improve the strength and corrosion resistance, and the RE and Ca act together to purify molten steel and modify and disperse inclusions. On the basis of component design, low-temperature heating, rough rolling multi-stage thickness section high-temperature gradient deformation and low-temperature rolling, intermediate temperature-waiting blank rapid cooling after rough rolling is finished, finish rolling low-temperature deformation, multi-stage water cooling and other methods are adopted to obtain a microstructure of lath bainite, granular bainite and polygonal ferrite, and the proportion, size and distribution control of all phases is ideal; the method plays an important role in obtaining good comprehensive performance of the steel plate.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2060MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After high-carbon chemical components containing trace V are designed, rolled and spun into a wire rod, the wire rod is cooled at a cooling speed of more than or equal to 33 DEG C / s through on-line molten salt semi-quenching treatment, enters a bainite and pearlite mixed phase region from an austenite state, and is subjected to hot rolling and hot rolling at a cooling speed of more than or equal to 33 DEG C / s; the method comprises the following steps: quenching bainite and a sorbite structure to form a structure mainly comprising the quenched bainite and the sorbite structure, then carrying out isothermal tempering, and finally carrying out roller way slow cooling to prepare the hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered sorbite and tempered bainite, so that a component system can be simplified, the material cost can be reduced, network carbides can be effectively controlled, and meanwhile, the complex-phase structure can be regulated and controlled; the high strength and plasticity of the wire rod are matched, the tensile strength is 1390-1440 MPa, the percentage reduction of area is 32%-37%, and the steel wire rod is used for manufacturing 2060 MPa grade stranded wires and other application fields and is beneficial to downstream wire drawing and twisting processing.

The invention relates to a 1200MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after V-containing chemical components are designed, rolled and spun into a wire rod, the wire rod is subjected to online molten salt isothermal quenching treatment, and the wire rod is controlled to enter a bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 32 DEG C / s; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared through isothermal tempering, toughening and destressing treatment, carbide precipitation control and roller way cover opening and slow cooling, so that generation of deteriorated structures such as martensite can be avoided, the structure state can be effectively adjusted, strong plasticity matching of the steel wire rod is achieved, and the service life of the steel wire rod is prolonged. And the tensile strength is 1120-110MPa, the percentage reduction of area is 63-67%, and the steel is suitable for the application fields of manufacturing 1200MPa-grade high-strength tool steel and the like, and is favorable for being directly processed into tool parts after being subjected to cold processing molding.

The invention relates to a 1100MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, the wire rod adopts a middle-carbon Nb-V-containing chemical component design, after a steel billet is rolled and spun into the wire rod according to the spinning temperature of more than or equal to 860 DEG C, online molten salt semi-quenching isothermal treatment is performed, the wire rod is controlled to be subjected to front-section molten salt treatment, and then the steel wire rod is subjected to hot rolling and hot rolling to obtain the 1100MPa-grade high-strength tool steel wire rod. According to the method, the steel wire rod enters a bainite phase region from a high-temperature austenite state at the cooling speed of more than or equal to 30 DEG C / s to form a structure taking quenched bainite as a main component, and then is subjected to rear-section molten salt heating isothermal tempering and toughening destressing treatment, and finally is subjected to roller way slow cooling to prepare the steel wire rod with a microscopic structure comprising tempered bainite and ferrite, so that the material cost can be reduced, and the production efficiency is improved. The method has the advantages that martensite brittle structures are effectively avoided, the structure state of the hot-rolled wire rod is controlled, the plasticity and cold working performance of the wire rod are improved, the tensile strength of the product can reach 980-1030 MPa, the percentage reduction of area is 61%-66%, and the product can be directly machined into tool parts after cold forming.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2230 MPa grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After a Nb-containing high-carbon component is used for rolling and spinning at a spinning temperature to form a wire rod, online molten salt mixing quenching isothermal treatment is carried out, so that the wire rod is firstly subjected to front-section molten salt treatment and is cooled at a cooling speed of more than or equal to 35 DEG C / s, and enters a bainite and pearlite mixed phase region from an austenite state; the method comprises the following steps: firstly, carrying out heat treatment on austenite to promote part of austenite to be converted into bainite and sorbite, then carrying out later-section molten salt treatment, increasing the molten salt temperature, promoting unconverted retained austenite to be decomposed and converted into sorbite, carrying out isothermal tempering, and finally, carrying out roller way slow cooling, so as to prepare the hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered bainite and tempered sorbite, the drawing and hardening capacity can be improved, the production efficiency is considered, the tensile strength is 1522-1572 MPa, and the percentage reduction of area is 29%-34%, so that off-line heat treatment is avoided, and the wire breaking risk and cost of stranded wire manufacturing are reduced.

The invention provides a method for obtaining the optimal low-temperature impact toughness and a welded body, and the method comprises the following steps: S1, obtaining chemical components of sample steel, and calculating the cooling rate corresponding to the bainite phase change curve nose tip temperature of the sample steel; s2, the cooling rate serves as the key cooling rate of the welding heat cycle process, and the corresponding welding heat input amount is calculated; s3, cutting a plurality of cuboid thermal simulation initial samples of which the length directions are parallel to the rolling direction of the steel plate from the sample steel; s4, two-pass welding thermal simulation cycle experiments at different temperatures are set; s5, two thermocouples are welded to the center of the cuboid thermal simulation initial sample for temperature measurement, and a welding simulation experiment is completed; and S6, size machining is conducted on the welding sample, a low-temperature impact experiment is conducted, impact energy under different technologies is measured, and the optimal impact toughness of CGHAZ and ICCGHAZ is determined. The method can be used for developing and optimizing the welding process with insufficient low-temperature impact toughness of the submerged-arc welding heat affected zone of the low alloy steel.

A method to achieve a yield ratio of 0.60 or more in a component from non-heat-treated steel having bainitic microstructure. The component includes a predetermined chemical composition, in mass %, in amounts such that a value of F1 obtained by Formula (1) is 0.65% or more, with the balance as Fe and inevitable impurity. Bainitic microstructure area fraction is 85% or more and Retained austenite area fraction is 5% or less. Crystal grains of the bainitic microstructure have an average diameter of 10 μm or more and 25 μm or less, an average aspect ratio of 0.5 or more, and an average ratio of crystal grain boundary length to crystal grain circumference of 60 or less.F⁢1=C+Si / 24+Mn / 6+Ni / 40+Cr / 5+Mo / 4+V / 14(1)

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2200MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod, and the manufacturing method comprises the following steps: rolling and spinning to form a wire rod by adopting a high-hardenability component design, and then carrying out online molten salt mixed phase region quenching isothermal treatment, so that the wire rod is firstly subjected to front-section molten salt treatment and enters a bainite and pearlite phase region from an austenite state; the method comprises the following steps: carrying out high-temperature treatment on austenite to promote part of austenite to be converted into bainite and sorbite, carrying out later-section molten salt treatment, increasing the molten salt temperature, reducing the molten salt circulation amount, promoting unconverted retained austenite to be decomposed and converted into bainite and sorbite, carrying out isothermal tempering, and finally carrying out slow cooling through a roller way, the hot-rolled wire rod with a microscopic structure comprising a complex phase structure composed of tempered bainite and tempered sorbite is prepared, the material cost can be reduced, the complex phase structure and the structure toughness can be regulated and controlled on line, the tensile strength is 1505-1555 MPa, the percentage reduction of area is 32%-37%, efficiency and energy consumption are both considered, off-line heat treatment is avoided, and high-efficiency production of stranded wires is promoted.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2360MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After a Mo-V high-carbon component system is rolled and spun into a wire rod, the wire rod is subjected to on-line molten salt weak quenching toughening treatment, so that the wire rod is subjected to front-section molten salt treatment to be quickly cooled, enters a bainite and sorbite mixed phase region from an austenite state, and is subjected to high-temperature heat treatment to form a high-strength complex-phase hot-rolled wire rod; the method comprises the following steps: firstly, carrying out heat treatment on residual austenite to form a structure mainly comprising bainite and sorbite, then carrying out later-section molten salt treatment, increasing the temperature of molten salt, promoting decomposition and conversion of unconverted residual austenite into sorbite, carrying out isothermal tempering, and finally, carrying out roller way slow cooling to prepare a hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered bainite and tempered sorbite, the method has the advantages that the structure toughness can be regulated and controlled on line, the tensile strength is 1574-1627 MPa, the percentage reduction of area is 28-33%, the mechanical property fluctuation is reduced, the material cost and the production efficiency are both considered, the ultra-high-strength stranded wire can be produced without off-line heat treatment, and the wire breaking risk is reduced.

The invention provides bainite non-quenched and tempered steel and a preparation method thereof.The preparation method comprises the following steps that blast furnace molten iron is sequentially subjected to molten iron pretreatment, converter smelting, ladle refining, vacuum refining, vacuum degassing, continuous casting and rolling, and the bainite non-quenched and tempered steel is obtained; the content of P at the smelting end point of the converter is less than or equal to And the content of S in the molten steel subjected to vacuum refining is 0.038%-0.045%. The bainite non-quenched and tempered steel with excellent comprehensive performance is obtained through reasonable smelting, refining, continuous casting and rolling process design of blast furnace molten iron designed by adopting specific chemical components, the preparation process is simple, and the preparation cost is low.

The invention relates to a detection method and application of a bainite steel structure and / or grain boundary for nuclear power equipment, and relates to the technical field of new material detection. According to the detection method, the problem that the structure and the grain boundary of bainite steel for nuclear power equipment are difficult to display can be solved, a major breakthrough of a grain size detection technology is achieved, the clear and complete grain boundary can be accurately presented, and scientific evaluation of the grain size through a comparison method, a cut point method, an area method and the like according to standard requirements is further supported. When the detection method is used for evaluating the grain size, the results are highly consistent, the repeatability is good, and the problems of subjective experience dependence and measurement errors caused by blurred grain boundary display in a traditional nitric acid and alcohol corrosion method are effectively avoided.

The invention discloses a high-carbon high-alloy grinding ball steel rolling internal damage control method, and belongs to the technical field of metal material rolling machining. Comprising the following steps that high-carbon high-alloy grinding ball steel billets are subjected to high-temperature diffusion homogenization treatment and then subjected to staged temperature control rolling, the initial rolling temperature in the blooming stage is 1020-1080 DEG C, the single-pass reduction rate is 6-10%, the pass interval is larger than or equal to 20 seconds, the total reduction rate is 40-80%, and the core peak temperature is controlled to be smaller than or equal to 1150 DEG C; the finish rolling temperature is 800-850 DEG C; during rolling, atomized water is sprayed for dynamic cooling every 2-3 passes, and two-stage cooling (water cooling to 600-650 DEG C at 15-20 DEG C / s, and slow cooling to room temperature) is carried out after final rolling. According to the method, element diffusion, temperature rise inhibition and structure refinement are synergistically regulated and controlled, so that the core void ratio is reduced, the austenite grain size is larger than or equal to 8 grades, a uniform bainite and dispersed carbide composite structure is obtained, and the anti-fatigue performance of the grinding ball steel is remarkably improved.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2260MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod, after the high-carbon component design of C-Si-Mn-Cr-V-Nb-V is rolled and spun into a wire rod, the wire rod is subjected to online molten salt mixed quenching isothermal treatment, so that the wire rod is subjected to front-section molten salt treatment to be quickly cooled, enters a bainite and pearlite mixed phase region from an austenite state, and is subjected to hot rolling and hot rolling to form the high-strength complex-phase hot-rolled wire rod. The method comprises the following steps: carrying out first-stage molten salt treatment on austenite to promote transformation of part of austenite to bainite and sorbite, then carrying out later-stage molten salt treatment to increase the molten salt temperature, promoting decomposition and transformation of untransformed retained austenite into sorbite, carrying out isothermal tempering, and finally carrying out slow cooling through a roller way, a hot-rolled wire rod with a microscopic structure comprising a complex-phase structure composed of tempered bainite, tempered sorbite and ferrite is manufactured, the tensile strength is 1547-1597 MPa, and the percentage reduction of area is 27%-32%, so that when a high-strength stranded wire is manufactured, off-line heat treatment is not needed, the drawing pass number is reduced, and the wire breaking risk is reduced.

The invention relates to a 1300 MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after a Cr-Nb-V medium carbon component design is adopted for rolling and spinning to form a wire rod, the wire rod is subjected to online molten salt micro-quenching tempering treatment, the wire rod is controlled to enter a lower bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 31 DEG C / s, and a quenching structure mainly comprising quenching bainite is formed; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared by carrying out isothermal tempering and toughening destressing treatment on a quenched structure and finally carrying out roller way slow cooling, so that the material cost can be properly controlled, the strength and plasticity matching of the steel wire rod is improved, the tensile strength is 1255-1305MPa, and the percentage reduction of area is 58-63%, so that the steel wire rod can be directly processed into a part after being subjected to cold processing molding, and the service life of the steel wire rod is prolonged. And tool steel production energy consumption, cost reduction and efficiency improvement are facilitated.

The bainite plastic die steel comprises the following components in percentage by mass: 0.01-0.15% of C, 0.25-1.0% of Si, 0.5-2.0% of Mn, less than or equal to 0.045% of P, less than or equal to 0.015% of S, 2.0-5.0% of Cr, 1.01-2.0% of Ni, 0.0010-0.0050% of B, 0.004-0.008% of N and the balance of Fe and other inevitable impurities, and the following requirements are simultaneously met: the hardness index is more than or equal to 28 and less than or equal to 13.8 + 132.8 C + 2.34 Mn + 1.84 Cr-1.12 Ni and less than or equal to 38, and the bainite index is C 0.5 * Mn 1.4 * Cr 4 * Ni * N-1. 05 / 20 and less than or equal to 2000. According to the die steel, the tensile strength is larger than or equal to 800 MPa, the hardness is 28-38 HRC, the hardness difference value of the section of a steel plate with the thickness of 15-300 mm is smaller than or equal to 2 HRC, the straightness is smaller than or equal to 2 mm / m, and the flaw detection quality meets the E / e level requirement in the SP1921-84 standard. The method can be applied to manufacturing of plastic parts in the fields of automobiles, household appliances, medical treatment, electronics and the like.

The invention relates to a high-plasticity wire rod for a hand tool and a manufacturing method of the high-plasticity wire rod, and the manufacturing method comprises the following steps: carrying out rolling, spinning, on-line molten salt isothermal toughening and roller way slow cooling treatment on a steel billet to prepare the wire rod with a microscopic structure comprising tempered bainite and ferrite, phase change and isothermal toughening treatment of the wire rod in a ferrite and bainite mixed phase region are controlled through online molten salt isothermal toughening, the wire rod adopts Cr-V chemical component design, the content of alloy elements such as Mn and V is relatively low, the online molten salt isothermal toughening technology is combined, the material cost and the mechanical property fluctuation of the wire rod can be reduced, the plasticity and cold machining performance of the wire rod are effectively improved, and the service life of the wire rod is prolonged. The tensile strength of the wire rod is 910-960 MPa, the percentage reduction of area is 58%-65%, extra heat treatment before cold machining of a hand tool is omitted, the cracking risk of direct cold machining of the wire rod is reduced, and the machining cost of the hand tool is reduced.

The invention relates to the technical field of metal material manufacturing, and discloses a manufacturing process of a super-strong wear-resistant tire protection chain, which comprises the following steps of: forming a chain link blank by adopting high-silicon high-manganese bainite steel through hot rolling and hot die forging; the core of the method is an integrated heat treatment step, specifically, surface functionalization co-permeation of copper and cerium elements is synchronously carried out in the austenitizing stage, then bainite isothermal quenching is carried out, and a composite structure of bainite and stable retained austenite is obtained in a matrix; the process further comprises the steps that a special high-toughness welding wire is adopted for welding, and local tempering treatment is conducted on a welding seam; by means of the scheme, the chain link is endowed with excellent obdurability and fatigue resistance through the phase transformation induced plasticity effect of the base body, the abrasion resistance is remarkably improved through the surface functionalization co-cementation layer, and the reliability of a joint area is ensured through accurate welding and postweld treatment. The technical problems that wear resistance and toughness of a traditional protection chain are difficult to consider at the same time, and a welding joint is prone to failure are systematically solved.

According to the high-strength complex-phase hot-rolled wire rod for the 2300 MPa grade stranded wire and the manufacturing method of the high-strength complex-phase hot-rolled wire rod, after Mo-V high-carbon components are rolled and spun into the wire rod, online molten salt section quenching isothermal treatment is conducted, the wire rod is subjected to front-section molten salt treatment and cooled at the cooling speed larger than or equal to 39 DEG C / s, the wire rod enters a bainite phase region from an austenite state, and then the high-strength complex-phase hot-rolled wire rod is obtained; the method comprises the following steps: carrying out high-temperature treatment on austenite to promote part of austenite to be converted into bainite, then carrying out later-section molten salt treatment, increasing the molten salt temperature, promoting unconverted retained austenite to be decomposed and converted into sorbite, carrying out isothermal tempering, and finally carrying out roller way slow cooling to prepare the hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered bainite, tempered sorbite and ferrite, by means of the method, complex-phase structure regulation and control and online toughening can be achieved, the material cost and the production efficiency are both considered, the tensile strength is 1552-1602 MPa, the percentage reduction of area is 32%-38%, and therefore off-line heat treatment is avoided, and ultrahigh-strength stranded wires are efficiently produced.

Provided is a steel sheet that may be used for automobile parts and the like, and to a steel sheet having an excellent balance of strength and ductility, an excellent balance of strength and hole expansion ratio, and an excellent yield ratio evaluation index, and a method for manufacturing the same. The steel sheet includes: by wt %, C: 0.1 to 0.25%, Si: 0.01 to 1.5%, Mn: 1.0 to 4.0%, Al: 0.01 to 1.5%, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, B: 0.0005 to 0.005%, a balance of Fe, and unavoidable impurities; and as microstructures, bainite, tempered martensite, fresh martensite, retained austenite and unavoidable structures.

The invention provides 500MPa-grade mining anti-corrosion anchor rod steel and a production method thereof. The 500MPa-grade mining anti-corrosion anchor rod steel comprises the following components: 0.09 to 0.12 percent of C, 0.60 to 0.70 percent of Si, 0.90 to 1.00 percent of Mn, 1.34 to 1.40 percent of Cr, 0.070 to 0.080 percent of V, 0.70 to 0.80 percent of Ni, less than or equal to 0.025 percent of P, less than or equal to 0.010 percent of S and the balance of Fe and inevitable impurities. Compared with the prior art, the production method is simple, the component design is reasonable, the quality of a casting blank can be improved, the strength and impact performance of a rolled material are guaranteed, meanwhile, the stress corrosion crack sensitivity is reduced, and the corrosion resistance is improved. The obtained microscopic structures of the product are ferrite and pearlite structures, bainite and other hardening phases do not exist, good matching of strength, plasticity and corrosion resistance is achieved, the corrosion-resistant anchor rod product completely meets the use requirements in the mine environment, and the product quality is improved.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2330MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After a Mo-containing high-carbon component is rolled and spun into a wire rod, the wire rod is subjected to online fused salt mixed quenching toughening treatment, so that the wire rod is subjected to front-section fused salt treatment and is rapidly cooled, and enters a bainite and sorbite mixed phase region from an austenite state; the method comprises the following steps: firstly, carrying out heat treatment on residual austenite to form a structure mainly comprising bainite and sorbite, then carrying out later-section molten salt treatment, increasing the temperature of molten salt, promoting decomposition and conversion of unconverted residual austenite into sorbite, carrying out isothermal tempering, and finally, carrying out roller way slow cooling to prepare a hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered bainite and tempered sorbite, according to the hot-rolled steel wire rod, complex-phase structure regulation and control and online toughening can be achieved, the production efficiency is considered, the tensile strength of the hot-rolled steel wire rod can reach 1563-1613 MPa, the percentage reduction of area can reach 29%-34%, offline heat treatment is not needed when the ultrahigh-strength stranded wire is produced, and the wire breaking risk is reduced.

The invention belongs to the field of metal materials, and provides 800MPa-grade alloyed galvanized complex phase steel with ultrahigh reaming performance for automobiles and a preparation method of the 800MPa-grade alloyed galvanized complex phase steel, and the steel plate comprises the following components in percentage by weight: 0.12%-0.17% of C, 1.90%-2.25% of Mn, 0.30%-0.65% of Si, 0.020%-0.040% of Ti, less than or equal to 0.030% of P, less than or equal to 0.002% of N, less than or equal to 0.005% of S and the balance of Fe and inevitable impurities. The preparation method comprises the steps of smelting, hot rolling, acid pickling, cold rolling, continuous annealing galvanizing and finishing. The microstructure of the steel plate produced by the method is mainly composed of bainite and tempered martensite, and the steel plate has ultrahigh hole expansion rate and excellent forming performance.

Provided is a steel sheet characterized by having a prescribed chemical composition and in that: the metal structure thereof contains, in terms of area%, 10-40% of ferrite, 60-90% of martensite, 0-10% of bainite, and a total of 0-5% of at least one among pearlite and retained austenite; and when a 150 μm × 150 μm region at a position at 1 / 4 of the sheet thickness in a cross section perpendicular to the sheet surface is equally divided into nine regions, the number density of ferrite in each of the divided regions is calculated, and the average value thereof is indicated by Nαm, the difference in the number density of ferrite between divided regions adjacent to each other in the sheet thickness direction is Nαm × 0.60 or less in all cases. Also provided are a component including the steel sheet, and a method for manufacturing the steel sheet.

The invention discloses an anti-oxidation packaging material for hot rolling of thermoelectric materials and a preparation method of the anti-oxidation packaging material, and relates to the technical field of new materials. The packaging material is of a three-layer composite tubular structure and sequentially comprises, from inside to outside, an anti-oxidation barrier layer which is a composite material with an Fe-Al intermetallic compound as a matrix and Y2O3 particles dispersed and distributed; the transition layer is a Ni-Cr-Fe-Mn-C series solid solution alloy with Ni as a matrix; and the structure supporting layer is made of microalloyed low-carbon bainite steel. The layers are metallurgically bonded through hot isostatic pressing, and then the hollow composite pipe is manufactured through cold drawing. The packaging material has excellent high-temperature oxidation resistance, good plastic deformation capacity and structural strength, can effectively isolate oxygen, coordinate strain and maintain overall integrity in the high-temperature hot rolling process, is suitable for protection and densification of Bi2Te3-based, PbTe-based and SiGe-based thermoelectric materials and the like, and remarkably improves thermoelectric performance and production consistency of the thermoelectric materials.

A high strength steel sheet having 1180 MPa or higher tensile strength and a method for manufacturing the same are disclosed. The high strength steel sheet has a specific chemical composition and is such that in a region at ¼ sheet thickness, the area fraction of martensite is 80% or more, the volume fraction of retained austenite is 3% or more and 15% or less, the area fraction of the total of ferrite and bainitic ferrite is 10% or less, the average grain size of prior austenite is 20 μm or less, and the average of the proportions of packets having the largest area in prior austenite grains is 70% by area or less of the prior austenite grain.

One embodiment of the present invention provides a high-strength thin-wall API steel material having excellent deformation stability and a manufacturing method thereof, the thin-wall API steel material comprising, in weight %, C: 0.05-0.15 %, Si: 0.5 % or less (except 0 %), Mn: 0.5-2.5 %, Nb: 0.05 % or less (except 0 %), V: 0.004 % or less (except 0 %), Mo: 0.03-0.2 %, Cr: 0.1-0.3 %, P: 0.03 % or less (except 0 %), S: 0.015 % (except 0 %), Al: 0.05 % or less (except 0 %), N: 0.01 % or less (except 0 %), Fe and other inevitable impurities in a balance, and a microstructure comprising, in area %, 10-30 % of ferrite having an average grain size of 15-30 μm and a balance of bainite, the thin-wall API steel material comprising 3000 / μm 2 V-based precipitates below.

The invention relates to a low-yield-ratio hot-rolled quenched and tempered steel plate with yield strength of more than 1100MPa and a production method thereof. The steel plate comprises the following components: 0.14%-0.17% of C, 0.15%-0.25% of Si, 1.15%-1.25% of Mn, less than or equal to 0.015% of P, less than or equal to 0.003% of S, 0.001%-0.01% of Al, 0.45%-0.55% of Mo, 0.3%-0.4% of Cr, 0.3%-0.5% of Ni and the balance of Fe and impurities. The component design that Cr, Mo and Ni are added into low-carbon steel is adopted, the hot-rolled steel plate is produced through smelting, continuous casting, rolling and hardening and tempering, the yield strength of the finished steel plate is larger than or equal to 1100 MPa, the tensile strength ranges from 1120 MPa to 1300 MPa, the hardness is larger than or equal to 350 HBW, the ductility is larger than or equal to 8%, and the structure is tempered martensite and bainite; a continuous heat treatment transverse cutting process is applied to production, and the steel plate with the thickness smaller than or equal to 6 mm, the maximum width of 1500 mm, high low-temperature impact toughness, low yield ratio and high wear resistance is rapidly and efficiently produced.