| 摘要 |
A cold reduced, non-aging, aluminum killed steel characterized by an elongated grain structure and having an r m value at least 1.8 produced from a slab having a reduced hot rolling temperature. A slab consisting essentially of ~ 0.08% carbon, ~ 0.1 % acid sol. aluminum, ~ 0.2% manganese, all percentages by weight, the balance iron and unavoidable impurities, is hot rolled to a sheet from a temperature less than 1260.degree.C. Preferably, the slab is continuously cast from a melt consisting essentially of 0.03-0.08% acid sol. aluminum, 0.003- 0.007% total nitrogen, ~ 0.20% manganese, wherein % acid sol. aluminum x % total nitrogen is within the range of 1 x 10-4 to 5 x 10-4 and is hot rolled from a temperature of 1093-1175.degree.C. The hot rolled sheet is descaled, cold reduced, batch annealed and temper rolled. Preferably, the cold reduced sheet is annealed in the range of 538-649.degree.C and the temper rolled sheet has a tensile strength of 29-32 kg/mm2, a total elongation of at least 42% and an r m valu e of at least 2.0. |
