Poka - Yoke in Welding

Abstract

Integral Coach Factory is the Premier Coach (ICF) building Industry in Indian Railways. This factory has so far produced more than 30000 coaches in about 170 designs. It was the first among the Indian Railway production units to get ISO 9001 certification. Quality of the coach is being ensured from the raw material to end product. In ICF. fabrication of coaches are being carried out by welding process. Though welding is a reliable metal joining process, the soundness of the weldment largely depends on Men, Machine, Material and Method. The quality of the weldment is ensured by implementation of various quality tools. Even then it is quite difficult to achieve 100% defect free product in manufacturing. Even if 100% inspection is resorted to at every stage of manufacturing defects are inevitable since the inspection is being carried out by human and human errors are inadvertent and inevitable. Poka-Yoke is a tool which achieves 100% defect free product at low cost with the aid of low cost equipments. These low cost equipments aids the employee to manufacture defect free product. The aim of this study is to develop Poka-Yoke methods in a welding application. Few parameters which affect the quality of the weld are identified, and various methods are developed to control these parameters and eliminate defects. The parameters identified are shielding gas flow rate, pre and post heat temperature, welding sequence and electricity. These parameters are recorded in a standard format. Poka-Yoke Techniques were applied to control the above said parameters and ensure error free welding in ICF.