Abstract
One of the major factors influencing weldability of stabilized 17 wt% Cr ferritic stainless steels is extensive grain coarsening in the fusion zone (FZ) and in the heat affected zone (HAZ). This study aimed at exploiting low heat input characteristics of laser welding to effectively control grain coarsening in the FZ and HAZ of 1.2-mm thick stabilized 17 wt% Cr ferritic stainless steel weldment. The study demonstrated that as compared with gas tungsten arc welding (GTAW), laser welding brought about significant grain refinement in the FZ and HAZ. Laser weldments exhibited superior ductility over their GTA counterparts. An important observation of the study was that, in contrast to GTA weldment, laser weldment was associated with weaker interfaces along columnar grain boundaries in the FZ that served to arrest crack propagation normal to them.
7.0 Acknowledgment
The authors are thankful to Mr. Sriram Chauksey of Eicher Motors, Pithampur, for arranging tensile testing of welded specimens. They also thank Mr. A. K. Singh for carrying out chemical analysis. The technical assistance of Mr. CH Prem Singh, Mr. Ram Nihal, Mr. Devendra Kumar, and Mr. J. B. Rathi at various stages of this study is also thankfully acknowledged.