PURPOSE: To obtain the titled stainless steel pipe having excellent corrosion resistance and mechanical properties by subjecting the titled steel pipe contg. Ti and/or Nb to hot rolling at a prescribed temp. or below and quick cooling right after hot rolling, then subjecting the steel pipe to final hot rolling and further to quick cooling at a specified cooling rate or above.
CONSTITUTION: The austenitic stainless steel contg. 0.1W0.6wt.% Ti and/or 0.2W1.5wt.% Nb is produced by hot working. The hot working right after the final hot working is executed by hot rolling and at ≤700°C and in this case, the heating temp. thereof is preferably set at (the heating temp. of the final hot rolling + 30°C) W 1,280°C and in succession, the quick cooling is executed. The final hot working of the above-mentioned steel pipe after the quick cooling is executed by hot rolling and the end temp. of said hot rolling is set at ≥950°C to allow carbide to solutionize and work strain to remain. The steel pipe after the end of such hot rolling is in succession cooled at ≥500°C/hr cooling rate, by which the desired austenitic stainless steel pipe having the fine-grained structure is obtd.
SAWARAGI YOSHIATSU
ISEDA ATSURO
SAMEJIMA TOMIO
HIRANO SUSUMU
