Patent classifications
C21D8/0405
METHOD FOR MANUFACTURING A METAL SHEET WITH A ZnAl COATING AND WITH OPTIMIZED WIPING, CORRESPONDING METAL SHEET, PART AND VEHICLE
A coated metal sheet includes a steel substrate and a coating on at least one surface of the steel substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The coated metal sheet was subjected to a skin pass operation after coating. An outer surface of the metal coating has a waviness Wa.sub.0.8 of less than or equal to 0.55 μm.
Steel sheet for manufacturing press hardened parts, press hardened part having a combination of high strength and crash ductility, and manufacturing methods thereof
A steel sheet for the manufacture of a press hardened part is provided, having a composition of: 0.15%≤C≤0.22%, 3.5%≤Mn<4.2%, 0.001%≤Si≤1.5%, 0.020%≤Al≤0.9%, 0.001%≤Cr≤1%, 0.001%≤Mo≤0.3%, 0.001%≤Ti≤0.040%, 0.0003%≤B≤0.004%, 0.001%≤Nb≤0.060%, 0.001%≤N≤0.009%, 0.0005%≤S≤0.003%, 0.001%≤P≤0.020%. A microstructure has less than 50% ferrite, 1% to 20% retained austenite, cementite, such that the surface density of cementite particles larger than 60 nm is lower than 10{circumflex over ( )}7/mm.sup.2, and a complement of bainite and/or martensite, the retained austenite having an average Mn content of at least 1.1*Mn %. Press-hardened steel part obtained by hot forming the steel sheet, and manufacturing methods thereof.
WEAR-RESISTANT STEEL PLATE AND METHOD FOR PRODUCING SAME
The steel plate has a specific chemical composition, and a microstructure where a volume fraction of martensite at a depth of 1 mm from a surface of the steel plate is 95% or more, and at a depth of 1 mm from a surface of the steel plate, a Vickers hardness at 400° C. is 288 or more, and a Brinell hardness at 25° C. is 360 HBW10/3000 to 490 HBW10/3000.
COLD ROLLED STEEL SHEET
Provided is a cold rolled steel sheet with excellent press formability, which contains a binder satisfying specific requirements and wax satisfying specific requirements, and has a layer containing the wax in a specific mass ratio at a specific coating weight.
COLD ROLLED FLAT STEEL PRODUCT FOR PACKAGING AND METHOD FOR PRODUCING A STEEL FLAT PRODUCT
A cold rolled steel flat product for packaging made of a low carbon steel having a thickness of less than 0.49 mm and a method of making. The steel flat product has a martensite-free microstructure and represents a standard grade for packaging with tensile strengths from 300 to 550 MPa, which can be produced from a cold-rolled steel sheet with a carbon content from 0.01% to 0.1% by weight by inductive annealing of the steel sheet and subsequent water cooling for quenching the recrystallization-annealed steel sheet. To achieve flatness of 5 I-units or less, the induction annealed steel sheet is first primarily cooled in the manufacturing process to a take-off temperature at a rate of less than 1000 K/s, with the take-off temperature being below the transformation temperature of 723° C., and thereafter a secondary cooling by water cooling with a water temperature of less than 80° C. at a rate of more than 1000 K/s.
Steel sheet for manufacturing press hardened parts, press hardened part having a combination of high strength and crash ductility, and manufacturing methods thereof
A steel sheet for the manufacture of a press hardened part is provided, having a composition of: 0.15%≤C≤0.22%, 3.5%≤Mn<4.2%, 0.001%≤Si≤1.5%, 0.020%≤Al≤0.9%, 0.001%≤Cr≤1%, 0.001%≤Mo≤0.3%, 0.001%≤Ti≤0.040%, 0.0003%≤B≤0.004%, 0.001%≤Nb≤0.060%, 0.001%≤N≤0.009%, 0.0005%≤S≤0.003%, 0.001%≤P≤0.020%. A microstructure has less than 50% ferrite, 1% to 20% retained austenite, cementite, such that the surface density of cementite particles larger than 60 nm is lower than 10{circumflex over ( )}7/mm.sup.2, and a complement of bainite and/or martensite, the retained austenite having an average Mn content of at least 1.1*Mn %. Press-hardened steel part obtained by hot forming the steel sheet, and manufacturing methods thereof.
Method for Manufacturing a Product from a Flexibly Rolled Strip Material
A method for manufacturing a product from a flexibly rolled strip material includes the steps of: providing a strip material made from sheet steel; flexibly rolling the strip material such that a variable thickness is produced along the length of the strip material; electrolytically coating the strip material with a metallic coating material containing at least 93% of zinc by mass after the flexible rolling; heat treating at temperatures above 350° C. and below a solidus line of the coating material after the electrolytic coating; working a blank from the flexibly rolled strip material; and hot forming the blank.
Method for producing press-hardened components for motor vehicles
A method for making a vehicle body component includes forming a generally flat plate of unhardened, hot-formable sheet steel with a marginal shape which corresponds essentially to the developed configuration of the finished vehicle body component. The formed plate is hot-formed and hardened in a single press tool to define a sheet profile which corresponds to the configuration of the finished vehicle body component, and a surface coating is applied to the sheet profile.
METHOD FOR MANUFACTURING STEEL SHEET FOR COLD PRESS AND METHOD FOR MANUFACTURING PRESS COMPONENT
A method that improves stretch flange formability of a steel sheet by individual treatment matching a material of the steel sheet without performing heat treatment in a die. This method is a method for manufacturing a steel sheet for cold press, and the steel sheet is manufactured by heating an edge of the steel sheet to a temperature within a heating temperature range preset according to a microstructure of the steel sheet and cooling the steel sheet. A region, within an edge of the steel sheet subjected to shearing in a shearing step, where it is estimated that a stretch flange crack is likely to occur when a press component is formed by cold pressing is determined, and a site to be heated and cooled is set within the region. By press-forming the manufactured steel sheet, a target press component is manufactured.
HOT PRESS FORMING MEMBER HAVING EXCELLENT RESISTANCE TO HYDROGEN EMBRITTLEMENT, AND METHOD FOR MANUFACTURING SAME
The present invention pertains to a hot press forming member having excellent resistance to hydrogen embrittlement, and a method for manufacturing same. An aspect of the present invention provides a hot press forming member having excellent resistance to hydrogen embrittlement, the hot press forming member comprising a base steel plate and an alloy-plated layer formed on the surface of the base steel plate, wherein the alloy-plated layer contains pores such that pores having a size of 5 μm or less constitute 3-30% of the surface area of the alloy-plated layer as viewed in a cross-section taken in the thickness direction of the member.