| 摘要 |
PURPOSE:To eliminate the need for a soln. heat treatment without impairing the cold workability of a two-phase stainless steel stock by cooling the stock with water right after rolling the same at a prescribed finish temp. to once lower the surface temp. thereof down to a specific temp., then allowing the steel to cool. CONSTITUTION:The two-phase stainless steel stock having the two-phase structure consisting of a ferrite phase and austenite phase is rolled at >=960 deg.C finish temp. at the time of hot rolling said stock. The stock is rapidly cooled by water cooling in the rolling line right thereafter. The surface temp. of the stock is thereby once lowered down to <=600 deg.C in a short period of time. The above- mentioned stock is thereafter allowed to cool and the cooling is stopped to about the extent that the surface temp. is slightly increased by the heat retained therein. The precipitation of the sigma phase is thereby prevented and the need for the soln. heat treatment is eliminated without impairing the cold workability after the hot rolling. The cost of the heat treatment of the two-phase stainless steel is thus reduced. |
