Characterisation of submerged arc welding process using infrared imaging technique

Abstract

Infrared (IR) thermography is a technique used to measure temperature distribution of heat generation in manufacturing processes such as welding. IR thermography is a non-destructive and non-contact method, which makes it favoured for the arc welding process where interference with the welding process must be avoided. In this study, IR thermography is used to record the temperature history during the submerged arc welding (SAW) process experiment; and to validate the numerical model developed to simulate the said SAW process of a multi-pass circumferential weld on pressure vessel steel. The Flir Short Wave Infrared Radiometer (FSIR) is used during SAW experiments with the ESAB welding unit. The weld pool and the surrounding area are continuously monitored and their temperature recorded using a thermal camera. The recorded temperatures are plotted against time on Temperature-Time curves to reveal the temperature profiles of each welding cycle. Comparison of the resultant temperature profiles with those of the numerical model show good agreement. It is therefore concluded that temperature measurement through thermal imaging is a suitable method to characterize the temperature history of the SAW multi-pass circumferential weld, as well as to effectively validate the numerical.