Ferritic stainless steel pipe with excellent salt decomposition resistance in gaps, pipe end thickness increase structure, welded joint, and welded structure

摘要

This ferritic stainless steel pipe, in mass%, C: 0.001 to 0.100%, Si: 0.01 to 2.00%, Mn: 0.01 to 2.00%, P: 0.001 to 0.05%, S: 0.0001 to 0.005%, Cr: 10.5 to 20.0 %, Sn: 0.001 to 0.600%, Ti: 0.001 to 1.000%, Al: 0.001 to 0.100%, N: 0.001 to 0.02%, the balance being Fe and unavoidable impurities, the tube end thickness increasing portion at the end of the tube The gap spacing d (μm) formed at the end of the tube ^{satisfies the relationship of d≧Cr 2} /(1000Sn) (wherein Cr and Sn represent the content (mass %) of each element).