Abstract:
A flat steel product having a tensile strength of at least 1200 MPa and consists of steel containing (wt %) C: 0.10-0.50%, Si: 0.1-2.5%, Mn: 1.0-3.5%, Al: up to 2.5%, P: up to 0.020%, S: up to 0.003%, N: up to 0.02%, and optionally one or more of the elements “Cr, Mo, V, Ti, Nb, B and Ca” in the quantities: Cr: 0.1-0.5%, Mo: 0.1-0.3%, V: 0.01-0.1%, Ti: 0.001-0.15%, Nb: 0.02-0.05%, wherein Σ(V, Ti, Nb)≦0.2% for the sum of the quantities of V, Ti and Nb, B: 0.0005-0.005%, and Ca: up to 0.01% in addition to Fe and unavoidable impurities. The flat steel product has a microstructure with (in surface percent) less than 5% ferrite, less than 10% bainite, 5-70% untempered martensite, 5-30% residual austenite, and 25-80% tempered martensite, at least 99% of the iron carbide contained in the tempered martensite having a size of less than 500 nm.
Abstract:
A flat steel product having a tensile strength of at least 1200 MPa and consists of steel containing (wt %) C: 0.10-0.50%, Si: 0.1-2.5%, Mn: 1.0-3.5%, Al: up to 2.5%, P: up to 0.020%, S: up to 0.003%, N: up to 0.02%, and optionally one or more of the elements “Cr, Mo, V, Ti, Nb, B and Ca” in the quantities: Cr: 0.1-0.5%, Mo: 0.1-0.3%, V: 0.01-0.1%, Ti: 0.001-0.15%, Nb: 0.02-0.05%, wherein Σ(V, Ti, Nb)≦0.2% for the sum of the quantities of V, Ti and Nb, B: 0.0005-0.005%, and Ca: up to 0.01% in addition to Fe and unavoidable impurities. The flat steel product has a microstructure with (in surface percent) less than 5% ferrite, less than 10% bainite, 5-70% untempered martensite, 5-30% residual austenite, and 25-80% tempered martensite, at least 99% of the iron carbide contained in the tempered martensite having a size of less than 500 nm.
Abstract:
A high strength steel, including about 0.05 to about 0.25% of C, less than about 0.5% of Si, about 0.5 to about 3.0% of Mn, not more than about 0.06% of P, not more than about 0.01% of S, about 0.50 to about 3.0% of Sol. Al, not more than about 0.02% of N, about 0.1 to about 0.8% of Mo, about 0.02 to about 0.40% of Ti, and the balance of iron and unavoidable impurities, wherein the steel has a structure formed of at least three phases including a bainite phase, and a retained austenite phase in addition to a ferrite phase having a composite carbide containing Ti and Mo dispersed and precipitated therein, wherein the total volume of the ferrite phase and the bainite phase is not smaller than 80%, the volume of the bainite phase is about 5% to about 60%, and the volume of the retained austenite phase is about 3 to about 20%.
Abstract:
A method for producing a metallic component (B) allows adjoining zones (Z1, Z2, Z3) having differing material properties to be produced in a manner which is simple in terms of production. This is achieved in that a sheet metal element (E) heated to a forming temperature is shaped in a forming tool (1) into an end-shaped component (B), wherein the forming tool (1) has a temperature adjustment means for adjusting the temperature of at least one of the portions (5, 7, 16) thereof that comes into contact with the sheet metal element (E) during the forming process, and in that the forming speed is controlled in consideration of the time for which the portion (5, 7, 16) of the forming tool (1) that is regulated with regard to the temperature thereof is in contact with the respective region (E1, E2, E3) of the sheet metal element (E) that rests against said portion.
Abstract:
A method, which allows high-tensile flat steel products to be manufactured with less effort includes a steel that forms a multi-phase microstructure and contains (in wt. %) 0.10-0.14% C, 1.30-1.70% Mn, up to 0.030% P, up to 0.004% S, 0.10-0.30% Si, 0.90-1.2% Al, up to 0.0070% N, 0.070-0.130% Ti, 0.040-0.060% Nb, 0.140-0.260% Mo, remainder iron and unavoidable impurities, being cast into a cast strip having a thickness of 1-4 mm. The cast strip is hot-rolled in-line into a hot-rolled strip having a thickness of 0.5-3.2 mm in a continuous process at a final hot-rolling temperature ranging from 850 to 1000° C., the deformation degree being greater than 20%. The hot-rolled strip is coiled at a coiling temperature ranging from 350 to 480° C., so as to obtain a hot-rolled strip, which has a minimum tensile strength Rm of 800 MPa at a minimum breaking elongation A80 of 5%.
Abstract:
A method, which allows high-tensile flat steel products to be manufactured with less effort, includes a steel that forms a complex phase microstructure and contains (in wt. %) C: 0.08-0.11%, Mn: 1.00-1.30%, P: ≦0.030%, S: ≦0.004%, Si: 0.60-0.80%, Al: ≦0.05%, N: ≦0.0060%, Cr: 0.30-0.80%, Ti: 0.060-0.120%, remainder iron and unavoidable impurities, being cast into a cast strip having a thickness of 1-4 mm. The cast strip is hot-rolled in-line into a hot-rolled strip having a thickness of 0.5-3.2 mm in a continuous process at a final hot-rolling temperature ranging from 900 to 1100° C., the deformation degree being greater than 20%. The hot-rolled strip is coiled at a coiling temperature ranging from 550 to 620° C., so as to obtain a hot-rolled strip, which has a minimum tensile strength Rm of 800 MPa at a minimum breaking elongation A80 of 10%.
Abstract:
A high strength steel sheet and a method for manufacturing the same has superior phosphatability properties and hot-dip galvannealed properties besides a tensile strength of 950 MPa or more and a high ductility, and also having a small variation in mechanical properties with the change in annealing conditions.
Abstract:
The invention relates to a method for producing hot strip which features good forming ability and increased strength. This is achieved in that a hot strip (W) which is produced in particular from continuous casting in the shape of reheated slabs or slabs obtained directly from the casting heat, from thin slabs or cast strip, based on a steel comprising (in mass %) C: 0.001-1.05%; Si: ≦1.5%; Mn: 0.05-3.5%; Al: ≦2.5%, if necessary further elements such as Cu, Ni, Mo, N, Ti, Nb, V, Zn, B, P, Cr, Ca and/or S, with the remainder being iron as well as the usual accompanying elements, is continuously finish rolled and subsequently continuously cooled, with cooling taking place in at least two subsequent cooling phases (tCK, tLK) of accelerated cooling, to a final temperature; with the first cooling phase (tCK) of accelerated cooling starting at the latest three seconds after the last pass of finish rolling; and with the hot strip (W) during the first cooling phase (tCK) of accelerated cooling being cooled at a cooling rate of at least 150° C./s.
Abstract:
The invention relates to a method for producing a shaped sheet-metal part from a panel or a semifinished part made of a material consisting of steel with at least 60 wt. % Fe and a residual austenite content of at least 5%, in which the panel or the semifinished part is at least partially cooled to a temperature below −20° C. before the shaping and is shaped at a temperature below −20° C. in a forming tool. The object of providing a method for producing load-compliantly configured components, which on the one hand permits industrial-scale use of low-temperature forming and is configured particularly simply, is achieved by reducing the material temperature of the panel or semifinished part to below −20° C. is carried out in a thermally regulated cooling apparatus.
Abstract:
The invention relates to a wheel rim for a motor vehicle which can be economically manufactured, with a wheel disc made of steel sheet and a rim flap running around the circumference of the wheel disc. Due to the fact that the steel sheet of the wheel disc is formed from at least three superimposed steel layers, joined to one another by roll-bonding in a non-detachable manner, of which the inner core layer has a lower strength than the outer layers, it is thereby guaranteed that the wheel rim according to the invention, with a low weight, can safely accommodate the forces arising in practical operation.