Effects of TIG welding process on microstructure, electrical resistance and mechanical properties of Nichrome 8020

Abstract

This study investigates effects of TIG welding and welding heat input on microstructure, hardness, tensile strength, fracture mechanism, and electrical resistance of Nichrome 8020 to evaluate its efficiency after welding, especially as a heating element. The post-weld microstructure of the alloy remained austenitic. The microstructure of fusion zone consisted of columnar dendrites, equiaxed dendrites, and intermetallic carbonitrides. These precipitates nucleated and grew among subgrain boundaries. Because of grain growth, hardness and tensile strength decreased after welding, and by increasing welding heat input, these mechanical properties decreased more severely. Fractography analysis showed that fracture surfaces of all the welded samples included both brittle and ductile features. Despite grain growth, which occurred as a result of the welding process, the electrical resistance of Nichrome 8020 increased slightly after welding. No signs of welding cracks and topologically close-packed phases were observed in the heat affected zone and fusion zone of any sample.

Effect of ATIG Welding Process Factors on the Wear Behavior of AISI 316L

“…JamshidiAval et al [7] studied the weld pool geometry and microstructure in GTAW of SS304. Afkhami and Halvaee [8] examined the effects of TIGW process on mechanical behaviour of Nichrome 8020.Vasudevan [9] investigated the influence of a TIGW process of 304LN and 316LN stainless steels. The impact of welding factors on the mechanical behaviourof Al-Mg-Si alloy [10].…”