| 摘要 |
The invention relates to a rolled-steel sheet or blank, the composition of which includes, the contents being expressed in wt %: C ≤ 0.1%, 0.5% ≤ Mn ≤ 7%, 0.5% ≤ Si ≤ 3.5%, 0.5% < Ti ≤ 2%, 2% < Ni ≤ 7%, Al ≤ 0.10%, Cr ≤ 2%, Cu ≤ 2%, Co ≤ 2%, Mo ≤ 2%, S ≤0.005%, P ≤ 0.03%, Nb ≤ 0.1%, V ≤ 0.1%, B < 0.005%, and N ≤ 0.008%, it being assumed that the silicon and titanium contents are such that Si + Ti ≥ 2.5% and that formula (I) is complied with. The remainder of the composition consists of iron and unavoidable impurities resulting from production. The invention also relates to the method for manufacturing a part for land-based motor vehicle from the sheet or blank by means of hot-drawing. The microstructure of the part essentially consists of martensite and intermetallic Fe2TiSi precipitates with an area ratio of between 1% and 5% for the latter. |
