ABSTRACT
The paper examines three main effects of welding, namely flaws, residual stresses, and macro/microstructural changes, but pays particular attention to aspects of flaws and their detectability in view of Sir Alan Cottrell’s special interest in this topic. The factors governing the incidence of large flaws and their size distribution are discussed, together with the main measures for their avoidance. Detectability of large flaws by radiography is reviewed and a recently proposed new index for predicting the probability of detection is explained. Progress in the detectability of flaws by ultrasonic inspection is then discussed. The paper reviews recent developments in residual stress determination and the benefits of standardised profiles, and finally discusses the main effects of welding on properties and microstructures of joints, particularly heterogeneity issues.
