10 results about "Ferritic matrix" patented technology

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 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.

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 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 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.

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 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.