31 results about "Ferritic matrix" patented technology

The invention belongs to the technical field of sliding component casting, and particularly relates to a cast iron sliding component and a preparation method thereof.The cast iron sliding component is made of silicon solid solution ferrite nodular cast iron, the structure of the material is uniform and single ferrite, and the cast iron sliding component comprises, by mass, 2.90%-3.20% of C, 3.9%-4.35% of Si, smaller than or equal to 0.4% and not larger than 0 of Mn, smaller than or equal to 0.04% and not larger than 0 of P, smaller than or equal to 0.02% and not larger than 0 of S and the balance Fe and inevitable impurities. The alloy comprises the following components in percentage by weight: less than or equal to 0.020% of S but not 0, 0.040-0.060% of Mg, 0.005-0.009% of Sb and the balance of iron and inevitable trace elements. The sliding component has a full-ferrite matrix structure and is good in structure uniformity, machining residual stress is reduced, meanwhile, the thermal expansion coefficient is reduced, nitriding deformation is avoided, annealing heat treatment is not needed after casting knockout and before honing, secondary honing after nitriding is omitted, and the non-uniformity of the final nitriding structure is reduced.

The application relates to the technical field of steel production, in particular to a hydrogen embrittlement resistant pipeline steel and a preparation method and application thereof. The metallographic structure of the pipeline steel comprises a tempered sorbite structure and nano precipitate particles; the tempered sorbite structure comprises a ferrite matrix and carbide; the grain size of the ferrite is greater than or equal to 10 levels, and the volume fraction of the carbide is less than or equal to 10%; the diameter of the nano precipitate particles is less than or equal to 20 nm. The application solves the technical problem that the existing pipeline steel is prone to hydrogen damage in a high-pressure hydrogen environment, avoids the contradiction between high strength and hydrogen embrittlement resistance, and makes the hydrogen conveying pipeline steel have high strength, high toughness, low hardness and excellent hydrogen embrittlement resistance, so that the hydrogen conveying pipeline steel can meet the use requirements of high-pressure (greater than or equal to 10 MPa) hydrogen conveying.

The application discloses an in-situ self-grown Al2O3 reinforced composite low-density steel and a hot deformation method thereof. The in-situ self-grown Al2O3 reinforced composite low-density steel comprises a steel matrix and Al2O3 reinforcing phases distributed in the steel matrix. The chemical components of the in-situ self-grown Al2O3 reinforced composite low-density steel are as follows in percentage by mass: Al2O3 is 2-5.5%, Al is 9-11%, Cu is 1.5-2.5%, C is 0.1-0.3%, and the balance is Fe and inevitable impurities. The grain size of ferrite in the steel matrix is in a bimodal distribution structure, and the average grain size is 20-60 mu m. The application can obtain the composite low-density steel which is synergistically reinforced by fine delta-ferrite matrix and small Al2O3 reinforcing phase particles, so that the microstructure and comprehensive mechanical properties of the composite low-density steel are significantly improved.

The present invention relates to a steel suitable for automotive materials, and more particularly to a high-strength steel sheet having excellent hole expansion and ductility and a method of manufacturing the same. The microstructure of the high-strength steel sheet of the present invention is composed of a hard phase and a soft phase, and by an optimized cold-rolling and annealing process, a martensite phase as the hard phase is uniformly distributed on a recrystallized ferrite matrix, and the crack resistance during processing can be improved by introducing a non-equilibrium ferrite phase at the interface of the hard phase and the soft phase.

The invention discloses easy-to-weld drawing-resistant low-alloy high-strength steel for a seat torsion bar and a production method, and belongs to the technical field of cold-rolled plate strip production in the metallurgical industry. The steel comprises the following chemical components in percentage by weight: 0.045 to 0.070 percent of C, 0.35 to 0.45 percent of Si, 1.2 to 1.5 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.001 percent of S, 0.02 to 0.05 percent of Als, 0.015 to 0.035 percent of Nb, 0.08 to 0.10 percent of Ti and the balance of Fe and inevitable impurities. And the carbon equivalent CE is equal to 0.245 to 0.320. Through component design and matching with hot rolling, acid rolling and continuous annealing processes, a ferrite matrix and a fine aging precipitated phase are obtained, the yield strength of the high-strength steel reaches 600-760 MPa, and the hardness of a weld joint after high-frequency welding is 1t; and 300 HV0.5 is achieved, and it is guaranteed that the weld joint of the welded pipe is not cracked in the chambering, flattening and special-shaped drawing processes.

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a preparation method of low-carbon light-weight high-strength high-hardness ferrite steel. The low-carbon light-weight high-strength high-hardness ferrite steel is obtained by carrying out two-phase region heat preservation treatment on to-be-treated steel, then carrying out rolling treatment, and then carrying out two-stage recrystallization heat treatment and continuous annealing treatment. A ferrite matrix and a multiphase structure of M / A island + kappa carbide are obtained based on tissue regulation and control, the strength and hardness of refined ferrite and M / A island are improved through online heat treatment, the M / A island and kappa carbide serve as an important way for regulating and controlling the toughness, the requirement for light weight of the steel is met in combination with component control, and the production cost is reduced. And the excellent comprehensive mechanical property of the light steel is ensured.

The invention discloses induction heat treatment high-carbon gear steel, and belongs to the technical field of machine manufacturing. The gear steel comprises the following chemical components in percentage by mass: 0.705%-0.995% of C, 0.5%-2.5% of Si, 0.1%-0.5% of Cr, 0.010%-0.3% of Mo, 0%-0.3% of Cu, 0%-0.2% of V, 0%-0.02% of Ti and O < lt >. 30 ppm, S < lt >; 0.025%, P < lt >; 0.025%, and the balance being Fe. The material is subjected to vacuum melting to obtain a cast ingot, then the cast ingot is heated to 1050-1100 DEG C for complete austenitizing and heat preservation to achieve alloy component homogenization, then the cast ingot is continuously forged into the needed size in the cooling process, and the final forging temperature is controlled to be 850-900 DEG C. The forge piece is heated at 780-820 DEG C, subjected to heat preservation for 1-8 hours, cooled to 600 DEG C at the cooling speed of 20 DEG C / min and then discharged out of a furnace, and a structure with spherical cementite distributed on a ferrite matrix can be obtained; or heating and normalizing at 850 DEG C to obtain a pearlite structure. After induction quenching, the surface hardness of the steel plate can reach 62-64 HRC, and the depth of a hardening layer is 0.5-5 mm. The surface structure is characterized by comprising carbide with the average size of 0.3-0.6 mu m, martensite with the length of 0.5-2 mu m and a fine grain structure with the length of 7-15 mu m.

The present invention discloses a spheroidizing processing device and process for a small-diameter GCr15 seamless bearing steel tube, which is applied in the technical field of spheroidizing processing of seamless bearing steel tubes. The present invention sets an outer cylinder structure, and through the coordinated use of a receiving component and an outer wall component, the heat in the outer wall component can be circulated and concentrated in the seamless bearing steel tube, so that the seamless bearing steel tube can quickly reach a preset temperature and be spheroidized efficiently, thereby not only reducing heat loss but also accelerating the spheroidizing processing efficiency of the seamless bearing steel tube. By setting an inner cylinder structure, and through the coordinated use of a placement component and a positioning component, a plurality of seamless bearing steel tubes can be dispersed to avoid contact and stacking between the seamless bearing steel tubes, and can ensure that all parts of the seamless bearing steel tube are evenly heated, so that the carbides in the microstructure of the seamless bearing steel tube are spheroidized and can be evenly distributed in the form of fine spheres on the ferrite matrix.

The invention relates to low-hardness copper-containing ferrite antiviral stainless steel for coinage and a preparation method of the low-hardness copper-containing ferrite antiviral stainless steel for coinage. 1.0 to 3.0 parts of Cu (copper); mn < = 0.4; si < = 0.3; carbon C is less than or equal to 0.04; phosphorus P < = 0.02; the weight percentage of the Cr to the Cu meets the condition that the Cu is less than or equal to 1 / 3 Cr-3.1. The specific preparation method comprises the following steps: smelting by adopting a vacuum induction furnace to obtain a raw material cast ingot, cogging, forging and hot rolling the cast ingot at 1100-1150 DEG C after coping the cast ingot, carrying out multi-pass cold rolling on a hot-rolled plate to obtain a cold-rolled plate, carrying out solution treatment at 950-980 DEG C, preserving heat for 0.5-1 hour, cooling to room temperature along with the furnace, preserving heat for 1-2 hours at 700-800 DEG C, and cooling to room temperature in air, and the low-hardness copper-containing ferrite antiviral stainless steel material for coinage is obtained. According to the preparation method, the addition amount of Cr and Cu is precisely regulated and controlled, meanwhile, a proper heat treatment system is combined, a copper-rich phase with the size of 300-800 nm is separated out from a ferrite matrix, meanwhile, generation of a hard martensite structure is avoided, a composite microscopic structure composed of full ferrite and the copper-rich phase with the large size is obtained, the microhardness value of the prepared copper-containing ferrite stainless steel is 130-150 HV10, and the copper-containing ferrite stainless steel has the good mechanical property and the good mechanical property. And the inactivation rate on the coronavirus reaches 90% or above.

This invention belongs to the field of metallurgical technology, and specifically relates to a high-surface-quality steel plate without transverse crease defects and its production method. The chemical composition, by weight percentage, is: C: 0.082%–0.104%, Si: 0.06%–0.10%, Mn: 0.32%–0.39%, P≤0.010%, S≤0.004%, O≤0.0015%, Alt: 0.025%–0.048%, N: 0.0012%–0.0025%, V: 0.014%–0.026%, B: 0.0006%–0.0016%, with the remainder being Fe and unavoidable impurities. By adding elements V and B, combined with hot rolling and leveling processes, the content of dissolved carbon and nitrogen atoms in the ferrite matrix is ​​reduced, allowing carbon and nitrogen atoms to exist in the form of precipitated phases. This reduces the formation of Cotillard atmospheres, lowers the stress difference between the upper and lower yield points, and results in stable coiling performance and excellent surface quality of the steel plate.

The present invention belongs to the technical field of iron and steel metallurgy, and more specifically relates to a method for preparing low-carbon, lightweight, high-strength, high-hardness ferritic steel. The present invention obtains low-carbon, lightweight, high-strength, high-hardness ferritic steel by subjecting the steel to be treated to a two-phase zone insulation treatment, followed by a rolling treatment, and then a double-stage recrystallization heat treatment and a continuous annealing treatment. The present invention obtains a multiphase structure of a ferrite matrix and M / A islands + κ carbides based on organizational regulation, and increases the strength and hardness of the refined ferrite and M / A islands through online heat treatment. M / A islands and κ carbides serve as important ways to regulate toughness. Combined with component control, they solve the demand for lightweight steel and ensure that lightweight steel has excellent comprehensive mechanical properties.

The invention discloses in-situ authigenic Al2O3 reinforced composite low-density steel and a thermal deformation method thereof, the in-situ authigenic Al2O3 reinforced composite low-density steel comprises a steel matrix and an Al2O3 reinforced phase distributed in the steel matrix, and the in-situ authigenic Al2O3 reinforced composite low-density steel comprises the following chemical components in percentage by mass: 2-5.5% of Al2O3, 9-11% of Al, 1.5-2.5% of Cu, 0.1-0.3% of C and the balance of Fe and inevitable impurities; the grain size of ferrite in the steel matrix is of a bimodal distribution structure, and the average grain size is 20-60 microns. According to the method, the composite low-density steel which is synergistically reinforced by a relatively fine delta-ferrite matrix and fine Al2O3 reinforced phase particles can be obtained, so that the structure and the comprehensive mechanical property of the composite low-density steel are remarkably improved.

The present application belongs to the technical field of cold-rolled automobile steel, and particularly relates to a low-cost 500MPa-grade hot-dip galvanized dual-phase steel plate with high hole-expanding performance and a preparation method thereof. The alloy composition system of C-Si-Mn-Cr is adopted. C is the most basic strengthening element. The appropriate Si element can 'purify' the ferrite matrix, guarantee the drawing performance, and the appropriate Mn and Cr elements are added to improve the hardenability of the steel, so that appropriate martensite structure is generated. Mo, Nb and other high-priced alloy elements are not added, thereby reducing the manufacturing cost of the product. By adopting LF+RH double refining, low superheat, reasonable hot rolling temperature, annealing temperature and other key parameters, the product organization is uniform, the grain is fine, there is no banded structure and no large-size inclusion segregation, the organization ratio is reasonable, thereby guaranteeing that the product has high hole-expanding performance and the application scene is greatly increased. On the other hand, by controlling the atmosphere and dew point in the furnace during annealing, the substrate has good wettability, the surface of the steel forms an Fe2Al5 inhibition layer during galvanizing, the adhesion of the galvanizing is improved, and good surface quality is obtained.

The application discloses a spheroidal graphite cast iron material and a preparation method and application thereof, and belongs to the technical field of cast iron alloy materials.The spheroidal graphite cast iron material is prepared from the following components in percentage by mass: C: 3.4-3.8%, Si: 2.3-2.7%, Mn: 0.1-0.3%, Zr: 0.03-0.06%, V: 0.03-0.08%, Ce: 0.03-0.06%, Mg: 0.02-0.05%, S: less than or equal to 0.04%, P: less than or equal to 0.04%, and the rest is iron and inevitable impurities.The spheroidal graphite cast iron material is mainly prepared from a ferrite matrix to ensure the toughness and safety of the spheroidal graphite cast iron material, and trace Zr elements and alloy elements V are added to control the structure, so that the hardness and strength of the material are improved, and the spheroidal graphite cast iron is improved in wear resistance, corrosion resistance and compression resistance.

A grade of ductile cast iron having a tensile strength (Rm) equal to or greater than 700 MPa, an elongation at break equal to or greater than 11%, a yield strength (Rp0.2) equal to or greater than 532 MPa, and a minimum ratio of yield strength (Rp0.2) to tensile strength (Rm) of 76% in a tensile test performed on a specimen taken from a tensile bar in accordance with standard EN 1563 and having a diameter of 25 mm and a length of 200 mm.

The invention discloses a high-strength and corrosion-resistant steel plate with a compact oxide layer formed on the surface, and relates to the technical field of weather-resistant steel plates and production processes thereof. A novel and stable ferrite matrix structure is designed through the elements C, Mn, Cr, Ni and Cu, a compact oxide layer is formed between a surface layer and a matrix after heat treatment by utilizing the stabilizing effect of the elements on a ferrite phase and the influence on a phase change structure, and the compact oxide film can protect the matrix below the surface layer to greatly relieve the corrosion speed, so that the corrosion resistance of the matrix is improved, and the service life of the matrix is prolonged. Oxygen and water in the atmosphere are effectively prevented from permeating into steel, and the corrosion resistance of a steel material is greatly improved. The obtained corrosion-resistant steel plate achieves balance of high strength and high toughness, meanwhile, the production technology is simple, large-scale production can be achieved, and the corrosion-resistant steel plate is more suitable for steel for steel structures exposed in the atmosphere for a long time for railways, vehicles, bridges, towers, photovoltaics, expressways and the like.

The invention relates to high-modulus steel and a preparation method thereof. The structure of the high-modulus steel comprises a ferrite matrix with the volume fraction being 86-88% and boronized particles with the volume fraction being 12-14%. The high-modulus steel has the characteristics of low density and high specific modulus, so that the requirements of steel for the fields of automobiles and the like with light weight and high rigidity requirements are met; according to the preparation method, by adopting a C-Cr-B component system and a high-temperature hot rolling-solution treatment mode process, the high-modulus steel with light boronized reinforced particles dispersed and distributed in a ferrite matrix is obtained; in the structure, boronized reinforced particles and a ferrite matrix form a coherent relationship, and the structure has strong binding capacity, so that the high modulus has good ductility and strength; and the high-temperature hot rolling process is adopted, continuous dynamic recrystallization can be achieved, stress concentration around boronized reinforced particles is restrained, the stress of the boronized reinforced particles and a ferrite matrix is evenly distributed, and therefore the machinability and the ductility of the high-modulus steel are improved.

The invention relates to alloyed galvanized hot-rolled high-strength steel and a preparation method, and belongs to the technical field of steel preparation. The high-strength steel comprises the following chemical components in percentage by mass: 0.05%-0.12% of C, 0.1%-0.4% of Si, 1.5%-2.0% of Mn, 0.01%-0.06% of Al, less than or equal to 0.01% of P, less than or equal to 0.003% of S, less than or equal to 0.2% of Cr, less than or equal to 0.03% of Mo, less than or equal to 0.02% of Cu, less than or equal to 0.03% of Ni, at least one of 0.01%-0.12% of Ti, 0.01%-0.04% of Nb and 0.01%-0.08% of V, and the balance of Fe and inevitable impurities. The microstructure of the high-strength steel comprises, by area ratio, 35%-65% of ferrite, 35%-50% of martensite and smaller than or equal to 15% of martensite, the grain size of the ferrite ranges from 2 micrometers to 6 micrometers, the grain size of the martensite ranges from 0.5 micrometer to 2 micrometers, and the grain size of the martensite ranges from 1 micrometer to 3 micrometers. Through chemical component design, microstructure regulation and control and optimization of the proportion and size of a precipitated phase, the strength and hardness of a ferrite matrix are improved, the hardness difference between the soft phase and the hard phase is reduced, and the reaming performance is obviously improved.

The present invention relates to the technical field of iron and steel metallurgy, and in particular to nano-precipitation strengthened easy-to-weld high-strength steel, ship steel plate and preparation method. The composition of the steel material includes 0.04-0.08% C, 2.4-2.8% Ni, 0.25-0.50% Si, 0.6-1.2% Mn, 1.0-2.0% Cu, 0.01-0.02% Ti, 0.4-0.6% Al, and the balance is Fe and impurities. The steel material promotes the precipitation of Cu+NiAl-rich nano-composite phases by adding Cu, Ni and Al. These nano-composite precipitates in a semi-coherent / incoherent relationship with the ferrite matrix can not only improve the strength of the heat-affected zone through the precipitation strengthening effect, but also inhibit the expansion of microcracks, thereby improving the strength and toughness of the heat-affected zone, making it particularly suitable for use as a ship steel plate.

The application discloses a non-adjustable steel with excellent fatigue resistance for automobile crankshafts and a production method thereof. The non-adjustable steel has the following chemical components in percentage by weight: C: 0.30-0.50%, Si: 0.25-0.60%, Mn: 0.50-2.00%, Cr: 0.15-0.45%, Nb+V+Ti: 0.10-0.35%, Al: 0.05-0.15%, S: 0.035-0.075%, P: less than or equal to 0.015%, Mg+Te: 0.01-0.03%, and the balance of Fe and inevitable impurities. The production method comprises the following steps: heating a steel billet, rolling and forging. The steel provided by the application has the following advantages: the rod material has a uniform structure of ferrite matrix + lamellar pearlite + intracrystalline ferrite, has good comprehensive mechanical properties of tensile strength and elongation after fracture, and has excellent fatigue resistance.

The invention discloses a high-volume-fraction B2 phase reinforced ferrite-based alloy and an efficient preparation method thereof, and relates to the technical field of alloy materials. The method comprises the following steps: selecting a high-purity raw material, and preparing a master alloy by adopting a vacuum induction melting-electroslag remelting process; a near-net-shape blank is obtained through homogenization treatment and high-temperature forging; then carrying out solution treatment; performing cold deformation, such as rolling, stretching or drawing, under low temperature conditions to induce martensite transformation (SIMT); and finally, a strengthened structure is obtained through aging treatment. By inducing martensite phase transformation through stress, the B2 phase precipitation rate can be remarkably increased, the heat treatment time is shortened, and the preparation efficiency is improved. The volume fraction of the B2 phase of the obtained alloy is greater than 30%, and the alloy has excellent mechanical properties. The method is simple in process, high in efficiency, low in cost and suitable for industrial preparation of the B2-phase reinforced ferrite-based high-temperature alloy.

The disclosure relates to a graphite steel wire rod, steel wire, graphite steel and manufacturing methods therefor to which sulfur is added and which have excellent cutting performance to that conventional free-cutting steel. Specifically, the disclosure relates to a graphite steel wire rod and steel wire, and manufacturing methods therefor, the rod and the wire comprising, by wt %, 0.60-0.90% of carbon (C), 2.0-2.5% of silicon (Si), 0.1-0.6% of manganese (Mn), 0.015% or less of phosphorus (P) (excluding 0), 0.031-0.3% of sulfur (S), 0.10-0.05% of aluminum (Al), 0.005-0.02% of titanium (Ti), 0.005-0.0020% of boron (B), 0.0030-0.0150% of nitrogen (N), and the balance of Fe and inevitable impurities. In addition, the present invention relates to graphite steel and a manufacturing method therefor, the steel comprising is same as above, having, as a microstructure, graphite grains distributed in a ferrite matrix, having a degree of graphitization of 90% or more, and containing 5% or less of MnS inclusions and pearlite in total.

A graphite steel available as a material for mechanical parts of industrial machines or automobiles, and more particularly, a steel wire for graphitization heat treatment and a graphite steel and methods of manufacturing the same. The graphite steel includes, in percent by weight (wt %), 0.6 to 0.9% of carbon (C), 2.0 to 2.5% of silicon (Si), 0.1 to 0.6% of manganese (Mn), 0.015% or less of phosphorus (P), 0.03% or less of sulfur (S), 0.01 to 0.05% of aluminum (Al), 0.01 to 0.02% of titanium (Ti), 0.0005 to 0.002% of boron (B), 0.003 to 0.015% of nitrogen (N), 0.005% or less of oxygen (O), and the remainder of iron (Fe) and inevitable impurities, and satisfying Equation (1) below: wherein graphite grains are distributed in a ferrite base as a microstructure and a graphitization rate is 100%, (1) −0.003<[N]−[Ti] / 3.43−[B] / 0.77<0.003, wherein in Equation (1), [Ti], [N], and [B] are wt % of titanium, nitrogen, and boron, respectively.

The invention discloses 800MPa-grade low-alloy high-strength steel as well as a preparation method and application thereof, and relates to the technical field of welding steel. The 800MPa-grade low-alloy high-strength steel comprises C, Si, Mn, Nb, Ti, Cr, B, N, P, S and the balance Fe and inevitable impurity elements. By optimizing the chemical components and proportion of the steel, B-Cr element coupling is adopted to replace elements such as Mo and Ni which are high in price in traditional easily-welded steel, the ferrite matrix high-strength easily-welded steel is obtained through accurate matching of alloy elements and a rolling process, and the alloy cost of ton steel can be remarkably reduced through the improved components; the prepared low-alloy high-strength steel is high in strength and easy to weld, and the softening rate of a welded joint is low; according to the steel, the excellent performance is guaranteed, meanwhile, the production cost is greatly reduced, and the application field is wider.

The invention discloses a high-broaching-property low-density steel plate for an automobile rear anti-collision beam and a preparation method of the high-broaching-property low-density steel plate, and belongs to the technical field of low-density steel. The steel plate comprises the following chemical components in percentage by mass: 0.08 to 0.20 percent of C, 4.2 to 5.7 percent of Mn, 3.2 to 4.34 percent of Al, 0.02 to 0.04 percent of Ni, 0.60 to 0.70 percent of Cr, 0.53 to 0.89 percent of Si, less than 0.005 percent of S, less than 0.007 percent of P and the balance of Fe and inevitable impurities. The preparation method comprises the steps of vacuum melting and casting, hot rolling, acid pickling, cold rolling and heat treatment. The room-temperature structure of the low-density steel is a ferrite matrix and carbides distributed on the ferrite matrix, the density is smaller than or equal to 7.48 g / cm < 3 >, the hole expansion rate is larger than or equal to 50%, the yield strength is larger than 368 MPa, the tensile strength is larger than 668 MPa, and the percentage elongation after fracture is larger than 26%.

The invention belongs to the technical field of metal material modification, and particularly relates to a preparation method of high-strength and high-plasticity duplex stainless steel with multiple heterostructures. According to the method, through multi-stage thermal-mechanical composite treatment, a multi-heterostructure is constructed in duplex stainless steel, and combination of high strength and high plasticity is achieved. The method specifically comprises the following steps: regulating austenite proportion through high-temperature solution treatment; fine island-shaped austenite is separated out from a ferrite matrix through high-temperature aging treatment, and phase composition heterogeneity is formed; high-density dislocation and deformation energy storage are introduced in multi-pass deformation treatment; the rolled material is partially or completely recrystallized through short-time high-temperature annealing, and structure heterogeneity with heterogeneous grain sizes is formed; through low-temperature long-time aging treatment in a miscible gap temperature range, a nano-scale Fe-rich region and a nano-scale Cr-rich region are formed in ferrite, namely, a nano-scale structure is separated, and nano-scale chemical heterogeneity is introduced. The tensile strength of the prepared duplex stainless steel is improved by 50% or above compared with that of a commercial hot rolling state, and the total elongation is kept to be 22% or above.

The present invention provides a calcium-containing graphite steel having excellent cutting performance, which contains calcium (Ca) and can form Ca-Al oxides that act as nuclei for graphitization to promote graphitization, and can generate Ca sulfides to improve machinability, and a method for producing the same. [Solution] The steel sheet contains, by weight, 0.60-0.90% carbon (C), 2.0-2.5% silicon (Si), 0.7-1.3% manganese (Mn), 0.2-0.5% sulfur (S), 0.01-0.05% aluminum (Al), 0.005-0.020% titanium (Ti), 0.003-0.015% nitrogen (N), 0.0001-0.050% calcium (Ca), with the remainder being iron (Fe) and unavoidable impurities. The steel sheet has a fine structure, graphite grains distributed in a ferrite matrix, a graphitization rate of 95% or more, and contains a total of 5% by weight or less of MnS inclusions and pearlite.

A bearing component for a roller bearing includes a main body that forms the bearing component and is made of an iron-containing material having a pearlitic base structure and / or ferritic base structure. The main body has at least one raceway designed such that at least one rolling body can roll thereon. Preferably, the material of the main body includes cast iron and the at least one raceway is an inductively hardened.

The invention discloses a high-strength corrosion-resistant steel plate with a compact oxide layer formed on the surface, and relates to the technical field of weather-resistant steel plates and production processes thereof. A novel and stable ferrite matrix structure is designed through the elements C, Mn, Cr, Ni and Cu, by means of the stabilizing effect of the elements on a ferrite phase, the influence of the elements on phase change and the behaviors of the elements in the heat treatment process, a compact oxide layer is formed between a surface layer and a matrix after ferrite with the chemical components is subjected to heat treatment, and due to the fact that the compact oxide layer is formed, the corrosion resistance of the ferrite is improved, and the service life of the ferrite is prolonged. The corrosion-resistant steel plate can protect a base body under the surface layer, the corrosion speed is greatly relieved, oxygen and water in the atmosphere can be prevented from permeating into steel, the corrosion capacity of a steel material is greatly improved, the obtained corrosion-resistant steel plate achieves balance of high strength, high plasticity and high toughness, meanwhile, the production technology is simple, large-scale production can be achieved, and the production cost is low. And the steel is more suitable for steel structures exposed in the atmosphere for a long time, such as railways, vehicles, bridges, towers, photovoltaics, high-abrasion and slow engineering and the like.

The present invention provides a method, a system and an electronic instrument for calculating the ferrite content in cast iron parts. The method for calculating the ferrite content in cast iron parts includes the following processes: obtaining multiple material samples of the cast iron part to be measured; heating the multiple material samples to 900 degrees Celsius at the same speed and cooling them to 300 degrees Celsius at different fixed cooling speeds; S3 obtaining a cooling speed coefficient and multiple cooling coefficient parameters according to the fixed cooling speed of each material sample, and constructing a cooling coefficient equation according to the multiple cooling coefficient parameters; obtaining the temperature-time change curve of the cast iron part to be measured; according to the temperature-time change curve, using the cooling coefficient equation and a preset ferrite generation rate equation, obtaining the change curve of the ferrite generation rate with time in the cast iron part to be measured; integrating the ferrite generation rate in the time interval when the ferrite generation rate occurs to obtain the content of the ferrite matrix in the cast iron part. It solves the problem that the ferrite content in cast iron parts cannot be accurately calculated in the prior art.