On the development of microstructures and residual stresses during laser cladding and post-heat treatments

In this article, laser cladding process with a blown powder feeding was used to deposit nickel-based IN-625 superalloy, cobalt-based hardfacing Stellite 6 alloy and high-vanadium CPM 10V tool steel onto a similar or dissimilar base material, respectively, to investigate the development and controllability of process-induced residual stresses in the clad and to analyse their correlation with microstructural evolutions of the clad and heat-affected zone (HAZ) during cladding and post-heat treatments. The residual stresses were evaluated using the hole-drilling method as per ASTM E837-95, whereas the microstructures were studied using X-ray diffractometer, optical microscope and scanning electron microscope. A particular attention was paid to combined effect of both clad and HAZ on the build-up of residual stresses in the clad. It is expected that the experimental results will form a useful addition to the existing knowledge with respect to the topic and, more significantly, to promote confidence on industrial applications of laser-clad IN-625, Stellite 6 and CPM 10V materials.