Application of iron-based powders in tungsten inert gas welding for 17Cr–10Ni–2Mo alloys

This study investigates the influences of specific flux powders, including FeF2, FeO, and FeS on the surface appearance, geometric shape, angular distortion, hot crack susceptibility, and metallurgical properties of 5-mm-thick 17Cr–10Ni–2Mo alloys welded using the tungsten inert gas (TIG) process. Results indicate that TIG welding with FeF2 powder produces a weld of satisfactory appearance. TIG welding with FeO and FeS powders results in a substantial increase in both the joint penetration and weld aspect ratio, thereby reducing angular distortion of the weldment. TIG welding with FeO and FeS powders increases the delta-ferrite content and decreases welding heat input, and tends to reduce hot crack susceptibility of the welds. This study demonstrates that the application of activated powder assisted TIG welding can improve the weldment performances.