| 摘要 |
PURPOSE:To produce high-quality hot strip sheets of a double-phase stainless steel at a high productivity while avoiding cracking caused by sigma-brittleness, by raising a final temperature of hot rolling of a steel sheet above a specified temperature, and lowering a coiling temperature below a specified temperature. CONSTITUTION:A double-phase stainless steel sheet mainly composed of Fe, Cr and Ni is hot rolled at a final temperature above 850 deg.C higher than the sigma-phase precipitation point. Just after finishing the hot rolling, the steel sheet is cooled at a cooling rate of 10 deg.C/sec or more to 600-750 deg.C, and then coiled. The coiling temperature shall be 600-750 deg.C; otherwise, sigma-phase grains would precipitate at a temperature higher than 750 deg.C. |
