Weld metal characterization of 316L(N) austenitic stainless steel by electron beam welding process

Abstract

Electron beam welding (EBW) is a fusion joining process that produces a weld by impinging a beam of high energy electron to the weld joint. EBW has been used widely due to its advantages like narrow weld zone and heat affected zone, low distortion and contamination etc. The present work is focused on EBW of 316L(N) austenitic stainless steel varying the welding parameters such as beam power and welding speed. This study is carried out by analyzing the mechanical and metallurgical properties of the welded material. The mechanical properties have been evaluated using tensile, impact, hardness and bend test in accordance with the ASTM standards. The metallurgical characteristics are further investigated through optical microscopy. The mechanical properties of the weld material are better than the parent material. The variations of the mechanical properties were related with the variations in the cooling rate of the weld metal. The change in the cooling rate has influenced the grain size which has in turn influenced the mechanical properties. The metallurgical factors such as the presence of the ferrite and its percentage were also considered to substantiate the variation in the characteristics of the weld metal.

Keywords: electron beam welding, 316L (N), beam current, gun voltage.