| 摘要 |
1529626 Steel sheet: heat-treatment ARMCO STEEL CORP 17 Feb 1976 [28 Feb 1975] 06163/76 Heading C7A A cold reduced and annealed steel containing in wt. per cent: C 0À02-0À1 Mn 0À1 -0À9 Nb 0À02-0À18 Al 0À01-0À08 P, S, Si, N, O residual amounts Fe balance in which Nb may be wholly or partially replaced by a stoichiometric amount of Zr, and Al may be replaced by Ti, has a 0À2% YS of 45-65 k.s.i., in combination with elongation # 25%, or a YS of # 90 k.s.i. with elongation < 10%. The steel is produced by vacuum degassing the melt, fully killing, casting, hot-rolling, coiling at # 705‹C, coldrolling with 40-70% reduction and annealing to achieve recovery without recrystallization in the case of high strength material, or full recrystallization for the lower strength alternative. Coiling may be at 538-705‹C, followed by annealing at 593-705‹C for 7 minutes to 24 hours in the case of high-strength material, or at 677-760‹C for # ¢ hour, or continuously at 815-927‹C for 7-10 minutes, in the case of fully recrystallized material. |
