| 摘要 |
A hot rolled steel sheet, consisting of a hot dip aluminized, shaped and heat treated sheet of low alloy steel of specified composition, is new. A novel hot rolled steel sheet consists of a steel of composition (by wt.) 0.15-0.5% (exclusive) C, 0.5-3% (exclusive) Mn, 0.1-0.5% (exclusive) Si, 0.01-1% (exclusive) Cr, less than 0.2% Ti, less than 0.1% Al, less than 0.1% P, less than 0.05% S, 0.0005-0.08% (exclusive) B, balance Fe and impurities. An Independent claim is also included for forming a part from the above steel sheet having a hot dip aluminized coating which is heated at more than 5 to 600 degrees C/s. or more after sheet forming and before heat treatment. Preferred Features: The sheet is hot dip coated in a bath of composition 2-3.5% Fe and balance Al, optionally with addition of 9-10% Si. |
