Improving TIG Welding Quality using DMAIC

Mahesh S. Shinde, Dr. K. H. Inamdar

Abstract: In this paper study of Gas Tungsten Arc Welding (GTAW) process used for Aerospace application; the material used is Maraging steel (MDN250). The weld defects are a major concern leading to rework; higher costs and thus affecting the delivery schedule of the job. The process starts with Welding of long seams and circular seams in the job; and subsequently carrying out the NDT to find any defects during welding. A number of defects are being observed in the welding Process. Defects in welding may be found out in two methods; i. e. by Radiographic Tests and by Ultrasonic Tests. The paper deals with an application of Six Sigma DMAIC (DefineMeasure-Analyze-Improve-Control) methodology in an industry which provides a framework to identify; quantify and eliminate sources of variation in an operational process in question; to optimize the operation variables. Six Sigma improves the process performance of the critical operational process; leading to better utilization of resources; decreases variations and maintains consistent quality of the process output.

Keywords: DMAIC Methodology, Gas Tungsten Arc Welding GTAW, Maraging Steel, Non-Destructive Testing NDT