| 摘要 |
<p>PURPOSE:To produce the martensitic stainless steel line pipe having excellent corrosion resistance and weldability by subjecting a martensitic stainless steel pipe having a specific compsn. to austenitization, temper treatment and cooling treatment under specific conditions. CONSTITUTION:The martensitic stainless steel pipe which is decreased in C to <0.02%, contains, by weight%, 11 to 14% Cr, 1.2 to 4.5% Cu, 4h1% Si, <=2% Mn, and 0.005 to 0.2% Al, decreased in the content of N to <=0.015% an the residue thereof consisted of the balance Fe and unavoidable impurities is made into a steel pipe, and thereafter, the steel pipe is austenitized at 920 to 1100 deg.C and is then cooled at a cooling rate above water cooling. After this steel pipe is subjected to the temper treatment at the temp. above 600 deg.C and below Ac1 temp., the steel pipe is cooled at the cooling rate above the air cooling, by which the martensitic stainless steel line pipe is produced.</p> |
