Paper Title
Effect of Post Weld Heat Treatment on Mechanical Properties of Hot Wire GTA Welded Joints of SA213 T91 Steel

Abstract
There is an increasing interest in understanding the processing and properties of Cr-Mo alloy steels. Of these steels, the modified 9Cr-1Mo steel known as T91/P91 has a wide range of industrial application. During welding this grade undergoes change in microstructure, increase in hardness and decrease in impact toughness. The present study is concerned with the comparative study of the effect of post weld heat treatment (temperature and soaking time) on the mechanical property of hot wire GTA welded SA213 T91 alloy steel tubes. The results of hardness and impact strength measurements suggest that post weld heat treatment of 2h at 760C is optimum to re-establish the strength of T91 steel after welding. Keywords - Hot Wire TIG, modified 9Cr-1Mo steel, post weld heat treatment, toughness