Heat affected zone and weld metal analysis of HARDOX 450 and ferritic stainless steel double sided TIG-joints

Abstract

In this study, AISI 430 and HARDOX 450 grade steel are joined using a double-sided tungsten inert gas welding process. The microstructural properties of weld metal and HAZ were evaluated by optical microscopy, energy dispersive spectroscopy, electron back scatter diffraction, elemental mapping, and X-ray diffraction analysis. As the results showed, an increase in welding current caused a large increase in the heat input to the welding pool, the penetration depth and the bead size. AISI 430 steel with Cr and Ni mixed with HARDOX 450 created new phases in the weld metal such as Cr7C3, Cr3Ni3, C23C6, matensite, Cr1.36 Fe0.52. The quantity and compound of martensite and carbides depended on the welding heat output and cooling degree.