FIRE-RESISTANT STEEL SUPERIOR IN WELD JOINT REHEAT EMBRITTLEMENT RESISTANCE AND TOUGHNESS AND METHOD OF PRODUCTION OF SAME

摘要

The present invention provides high temperaturestrength and fire-resistant steel superior in weld jointreheat embrittlement resistance and toughness which isproduced using steel of a room temperature strength ofthe 400 to 600N/mm2 class containing as main ingredientsC: 0.010% to less than 0.05%, Si: 0.01 to 0.50%, Mn: 0.80to 2.00%, Cr: 0.50% to less than 2.00%, V: 0.03 to 0.30%,Nb: 0.01 to 0.10%, N: 0.001 to 0.010%, and Al: 0.005 to0.10%, limiting the contents of Ni, Cu, Mo, and B, andsatisfying the relationship of 4Cr[%]-5Mo[%]-10Ni[%]-2Cu[%]-Mn[%] 0.