| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold rolled steel sheet good in heat spot resistance and abrasion resistance.SOLUTION: A cold rolled steel sheet contains, by mass%, 0.03 to 0.12% of C, 0 to 1.0% of Si, 0.2 to 0.8% of Mn, 0.03% or less of P, 0.03% or less of S and 0.05% or less of Al. It also contains one of 0.03 to 0.4% of Nb and 0.03 to 0.3% of V. Further each element satisfies 5×C%-Si%+Mn%-1.5×Al%<1 in a range of above described contents. The balance is Fe with inevitable impurities. An average grain diameter of carbide containing any of Nb, V and Ti as a deposition is set at 20 to 100 nm. By regulating a chemical composition and homogeneously dispersing the deposition, heat spot resistance and abrasion resistance are enhanced.SELECTED DRAWING: None |
