| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a cold rolled steel strip having superior surface even in the case of a steel grade liable to cause beltlike uneven brightness, by controlling heating conditions before hot rolling. SOLUTION: At the time of inserting, before hot rolling, an austenitic stainless steel slab containingδ-ferrite in an as-continuously-cast structure into a heating furnace and heating it, the slab is heated while regulating heating temperature T( deg.C) and heating time to >=1200 deg.C and >=40 min, respectively, in an atmosphere of oxygen concentration C02 (vol.%) satisfying the condition of the lower one between C02 <=0.06×T-71.2 or C02 <=5.0 vol.%. By the control of heating conditions, a dense scale layer is formed on the whole surface of the slab after heating and uneven scale of a hot rolled steel strip can be inhibited, and as a result, the cold rolled steel strip free from beltlike uneven brightness can be obtained.
|
