The maing process of steel sheet to reduce edge crack is characterised by forced-cooling of steel slab to a cooling rate between air cooling rate and critical cooling rate of martensite transformation from Ar, point to room temperature, heating at 1000- 1250 deg. C, finish hot-rolling at 800-950 deg. C, and coiling at 500-700 deg. C. The steel slab is composed of (in wt.%) 0.10-0.70% C, up to 0.40% Si, 0.30-1.50% Mn, up to 0.1% Al, up to 0.03% P, up to 0.03% S and balance Fe with inevitable impurites.
展开▼
