Patent classifications
C21D6/004
HEAT TREATABLE STEEL, PRODUCT FORMED THEREOF HAVING ULTRA HIGH STRENGTH AND EXCELLENT DURABILITY, AND METHOD FOR MANUFACTURING SAME
The present invention relates to a formed product used in vehicle components and the like, and to a method for manufacturing the same. The present invention provides heat treatable steel, a formed product using the same having ultra-high strength and excellent durability, and a method for manufacturing the same, wherein the heat treatable steel contains, in wt %, C (0.22-0.42%), Si (0.05-0.3%), Mn (1.0-1.5%), Al (0.01-0.1%), P (0.01% or less (including 0), S (0.005% or less), Mo (0.05-0.3%), Ti (0.01-0.1%), Cr (0.05-0.5%), B (0.0005-0.005%), N (0.01% or less), the balance Fe, and other inevitable impurities, Mn and Si satisfying Relationship formula (1), below, Mo/p satisfying Relationship formula (2), below: [Relationship formula 1] Mn/Si≧5 [Relationship formula 2] Mo/P≧15.
NICKEL-CHROMIUM-IRON ALLOYS WITH IMPROVED RESISTANCE TO STRESS CORROSION CRACKING IN NUCLEAR ENVIRONMENTS
A Ni—Cr—Fe alloy with improved resistance to stress corrosion cracking in nuclear environments, the alloy comprising 23-28 wt % Cr, 25-35 wt % Ni, <0.03 wt % C, <0.70 wt % Si, <1.0 wt % Mn, <0.015 wt % S, >0.35 wt % Ti, 0.15-0.45 wt % Al, <0.75 wt % Cu, and balance Fe and incidental impurities. The alloy may be used in steam generator tubing of a nuclear reactor. A method of producing an article includes: providing the alloy as disclosed herein; forming the alloy into the article by cold working the alloy to 20%; and heat treating the article.
COLD-ROLLED STEEL PLATE FOR HOT FORMING, HAVING EXCELLENT CORROSION-RESISTANCE AND SPOT-WELDABILITY, HOT-FORMED MEMBER, AND METHOD FOR MANUFACTURING SAME
An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).
HIGH STRENGTH STEEL PRODUCT AND METHOD OF MANUFACTURING THE SAME
A hot-rolled strip steel product is described having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.030%-0.10% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.010% S,<0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.30% Mo, 0%-0.15% Al, 0%-0.10% Nb, 0.10%-0.30% V, <0.020% Ti, 0%-0.0010% B, remainder being Fe and inevitable impurities, wherein the hot rolled strip steel product has a a microstructure comprising, in terms of volume percentages (vol. %), ferrite≥90, wherein the ferrite structure comprises bainite, at least 50% of polygonal ferrite and at most 10% quasi-polygonal ferrite, and wherein the steel strip product has an average hole expansion ratio≥50%, a yield strength (Rp0.2%) longitudinal to rolling direction of ≥660 MPa and a tensile strength≥760 MPa.
STEEL FOR MINING CHAIN AND MANUFACTURING METHOD THEREOF
A steel for mining chain and a manufacturing method thereof, wherein the steel has compositions by weight percentage: C: 0.20-0.28%, Si: 0.01-0.40%, Mn: 0.50-1.50%, P≤0.015%, S≤0.005%, Cr: 0.30-2.00%, Ni: 0.50-2.00%, Mo: 0.10-0.80%, Cu: 0.01-0.30%, Al: 0.01-0.05%, Nb: 0.001-0.10%, V: 0.001-0.10%, H≤0.00018%, N≤0.0150%, O≤0.0020%, and the balance is Fe and inevitable impurities. The manufacturing method comprises steps of smelting, refining and vacuum treatment, casting, heating, forging or rolling, and quenching and tempering heat treatment processes. The steel in the present invention has high strength and good impact toughness, good elongation and reduction of area. The steel can also resist stress corrosion cracking and have good weather resistance, wear resistance and fatigue resistance, which can be used in scenarios where the steel having high strength and toughness is required, such as construction machinery and marine engineering.
PROCESS FOR PRODUCING AN AT LEAST PARTLY QUENCHED AND TEMPERED SHEET STEEL COMPONENT AND AT LEAST PARTLY QUENCHED AND TEMPERED SHEET STEEL COMPONENT
The invention relates to a process for producing an at least partly quenched and tempered sheet steel component, where the process comprises the following steps: providing a sheet steel, at least partly austenitizing the sheet steel at a temperature of at least Ac1, at least partly hardening the at least partly austenitized sheet steel to give an at least partly hardened sheet steel component, where the at least partly austenitized sheet steel is cooled to a temperature below Ms, at least partly annealing the at least partly hardened sheet steel component at a temperature of less than Ac1 for producing an at least partly quenched and tempered sheet steel component. A further subject of the invention is an at least partly quenched and tempered sheet steel component.
CARBON STEEL AND AUSTENITIC STAINLESS STEEL ROLLING CLAD PLATE MANUFACTURING METHOD THEREFOR
Disclosed in the present invention is a manufacturing method for a carbon steel and austenitic stainless-steel rolling clad plate, comprising the steps of: (1) obtaining a blank material of a carbon steel layer and a blank material of a stainless-steel layer; (2) assembling blank materials; (3) cladding and rolling; (4) cold rolling; (5) first annealing; and (6) second annealing. The carbon steel and austenitic stainless-steel rolling clad plate has two unique annealing processes, so that the clad plate has the performance advantages of the austenitic stainless-steel and the carbon steel. In addition, further disclosed in the present invention is a carbon steel and austenitic stainless-steel rolling clad plate manufactured by this method.
HIGH STRENGTH AND CORROSION RESISTANT FERROCHROME ALLOY BULK AND ARTICLE COMPRISING THE SAME
A high strength and corrosion resistant ferrochrome alloy bulk is disclosed, which comprises, in weight percent: 30-68% Cr, 1.5-8% Ni, 1.6-6% C, and the balance Fe and incidental impurities, of which a Fe/Ni ratio is in a range from 5 to 10 and a Cr/C ratio is in a range between 10 and 33. Experimental data reveal that, samples of the high strength and corrosion resistant ferrochrome alloy bulk all possess hardness above HV400 and excellent corrosion resistance due to the high content of Cr. As a result, experimental data have proved that the high-strength and corrosion-resistant ferrochrome alloy bulk of the present invention has a significant potential to replace conventional high-strength stainless steels, so as to be widely applied in various industrial fields, e.g., aviation, transportation, marine facility components, chemical equipment and pipe fittings, engine parts, turbine blades, valves, bearings, building materials, and so on.
Dual-phase stainless steel, and method of production thereof
Provided herein is a dual-phase stainless steel having excellent carbon dioxide corrosion resistance, excellent sulfide stress corrosion cracking resistance, and excellent sulfide stress cracking resistance. The dual-phase stainless steel contains, in mass %, C: 0.03% or less, Si: 1.0% or less, Mn: 0.10 to 1.5%, P: 0.030% or less, S: 0.005% or less, Cr: 20.0 to 30.0%, Ni: 5.0 to 10.0%, Mo: 2.0 to 5.0%, Cu: 2.0 to 6.0%, N: less than 0.07%, and the balance Fe and unavoidable impurities, and has a structure that is 20 to 70% austenite phase, and 30 to 80% ferrite phase in terms of a volume fraction.
Grain-oriented electrical steel sheet and method for manufacturing same
Provided is a grain-oriented electrical steel sheet having better transformer iron loss property than conventional grain-oriented electrical steel sheets. A grain-oriented electrical steel sheet comprises: a steel substrate; a forsterite film on a surface of the steel substrate; and a Cr-depleted layer at a boundary between the steel substrate and the forsterite film, the Cr-depleted layer having a Cr concentration that is 0.70 times to 0.90 times a Cr concentration of the steel substrate.