A FERRITIC STAINLESS STEEL HAVING SUPERIOR SECONDARY WORKING EMBRITTLENESS RESISTANCE AND SUPERIOR HIGH TEMPERATURE FATIGUE CHARACTERISTIC OF WELDED PARTS

摘要

PURPOSE: A ferritic stainless steel having both characteristics of secondary processing brittleness resistance and high temperature fatigue characteristics at the same time in a weld zone is provided. CONSTITUTION: In a ferritic stainless steel comprising C 0.02 wt.% or less, Si 0.2 to 1.0 wt.%, Mn 0.1 to 1.5 wt.%, P 0.04 wt.% or less, S 0.01 wt.% or less, Cr 11.0 to 20.0 wt.%, Ni 0.1 to 1.0 wt.%, Mo 1.0 to 2.0 wt.%, Al 1.0 wt.% or less, Nb 0.2 to 0.8 wt.%, N 0.02 wt.% or less, Co 0.01 to 0.3 wt.%, V 0.01 to 0.3 wt.%, B 0.0002 to 0.0050 wt.%, a balance of Fe and other unavoidable impurities, the present invention is characterized in that the amount of Co, V and B satisfy the following inequality: 0.1 = £Co|+0.5x £V|+100x£B| = 0.5 wherein £M| satisfies the percent range of M element.