TIG WELDING METHOD OF SUPER FERRITIC STAINLESS STEEL

摘要

PURPOSE: A TIG(Tungsten Inert Gas) welding method of super ferritic stainless steel is provided to improve the mechanical performance of a welding part by securing the sufficient impact property of weld metal at normal temperature in TIG-welding the super ferritic stainless steel comprising 26Cr(Chromium)-2Mo(Molybdenum). CONSTITUTION: In a TIG welding method of super ferritic stainless steel comprising 24Cr-2Mo with stability ratio over 17 and PRE(Pitting Resistance Equivalent) number over 32 and 30Cr-4Mo with stability ratio over 20 and PRE number over 42, the nitrogen content of weld metal for 26Cr-2Mo is below 0.02wt% and for 30Cr-4Mo is below 0.01wt% and the welding heat input for 26Cr-2Mo is below 6kJ/cm and for 30Cr-4Mo is below 4kJ/cm in 20 liter/pure argon protective gas atmosphere. Accordingly, the super ferritic stainless steel sufficiently satisfies the impact property of the welding part at normal temperature when the welding heat input and nitrogen content are limited.