| This work was carried out in order to join dissimilar stainless steels(STS304 and STS430) by laser beam welding which had many advantages over conventional welding processes. In this work, laser welded specimens were compared with TIG welded specimens in microstructure analysis, mechanical properties and corrosion resistance tests. Laser welding resulted small heat-affected zone and low distortion due to low heat input, and thus weld defects like hot cracking, Cr-carbide precipitation and grain boundary coarcening at HAZ which usually occurred in TIG welding were prevented. Although microstructure of weldment in TIG welding was ferrite/martensite duplex structure, only ferrite structure was obtained in laser welding due to suppression of δ→γ transformation by rapid cooling. It could be known that laser welded specimens resulted better ductility, toughness, pitting and SCC resistance. |
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