In situ studies of full-field residual stress mapping of SS304 stainless steel welds using DIC

Large tensile residual stress is detrimental to the structural integrity of welded structures. As a result, it is very important to understand the residual formation during the welding process. In this paper, a new non-contact welding residual stress measurement technique based on digital image correlation (DIC) is proposed as a way to investigate residual stress formation. To investigate the stress evolution of the welded plate, we conduct a series of experiments by using this new method. High-temperature full-field strain obtained from DIC was computed by incremental theory to acquire stress increment. Stress evolution and residual stress were obtained by superimposing the stress increment. Hole-drilling residual stress measurements for verification were also implemented. The maximum difference, which was 37 MPa between the two methods demonstrated that this new technique was able to characterize the full-field welding residual stress during the welding process.