Joining of Duplex Stainless Steel by Plasma Arc, TIG, and Plasma Arc+TIG Welding Processes

Abstract 1.4462 duplex stainless steel (DSS) with a thickness of 6.8 mm was joined by plasma arc, Tungsten Inert Gas (TIG), and plasma arc + TIG welding processes. Impact toughness testing was carried out and fractographs were examined by Scanning Electron Microscopy (SEM). Microstructural analysis, ferrite content, and hardness survey of the weld zones were done while the variation in chemical composition was investigated with energy dispersive X-ray spectroscopy (EDX). Results were compared due to the heat inputs of the joints and the relation between microstructure, and toughness was explained. Promising results showed that plasma arc welding (PAW) and/or plasma + TIG welding, which are considered immature processes for DSS, can successfully be employed for increased productivity. Keywords: Duplex stainless steelEN 1.4462Ferrite contentFractureHybrid weldingMicrostructureMicrostructure-property relationPlasma arc weldingStainless steelTIG weldingToughnessUNS S31803WeldingX2CrNiMo22.5.3 ACKNOWLEDGMENTS The author would like to acknowledge Industeel, Teknokon Inc., Gedik Welding Inc., Esab AB Sweden, Assan Inc., and Cimtas Inc. for their technical support. In addition, Prof. Dr. E. Kaluc, Dr. L. Karlsson, and Dr. P. Toussaint are very much appreciated and acknowledged for valuable suggestions and technical support. Notes [ ]Values between square brackets are obtained from the steel producer.