| 摘要 |
PROBLEM TO BE SOLVED: To efficiently manufacture steel products for low temperature use used for steel structures for which stress corrosion cracking resistance is demanded, such as tanks and refining plants used for storage and transportation of various liquefied gases like liquefied ammonia, at low cost. SOLUTION: The steel containing, by mass %, 0.02 to 0.12% C, 0.05 to 0.5% Si, and 0.6 to≤1.8% Mn, is heated to a temperature range from 1,000 to 1,200°C and is then subjected to hot rolling at a draft≥50% in a recrystallization temperature region and at a draft≥30% in a non-recystallization temperature. The steel is cooled down to a temperature region from 400 to 600°C in average temperature in succession after the end of the rolling and is thereafter heated to a temperature range from a surface temperature of≥500 to≤Acl+50°C by using an induction heater of a frequency of 200 to 2,000 Hz and is then air cooled. COPYRIGHT: (C)2004,JPO
|
