| 摘要 |
The invention relates to a steel part, the composition of the steel of which comprises, the contents being expressed by weight: 0.040%≦̸C≦̸0.100%; 0.80%≦̸Mn≦̸2.00%; Si≦̸0.30%; S≦̸0.005%; P≦̸0.030%; 0.010%≦̸Al≦̸0.070%; 0.015%≦̸Nb≦̸0.100%; 0.030%≦̸Ti≦̸0.080%; N≦̸0.009%; Cu≦̸0.100%; Ni≦̸0.100%; Cr≦̸0.100%; Mo≦̸0.100%; and Ca≦̸0.006%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel consisting of at least 75% equiaxed ferrite, martensite in an amount not less than 5% but not exceeding 20%, and bainite in an amount not exceeding 10%. |
