INFLUENCE OF AN INTERMEDIATE LAYER ON THE RESIDUAL-STRESS FIELD IN A LASER CLAD

Large residual stresses are generally produced during laser surface treatments owing to their associated high thermal gradients and cooling rates. In laser clads the high tensile residual stresses usually obtained can produce cracking or limit the practical use of these deposits. To investigate the potential of intermediate layers in controlling the residual stresses, multilayer clads were produced on a high chromium martensitic steel, with an austenitic stainless steel as an intermediate layer and stellite 6, a cobalt-based alloy, as the surfacing material. The stress profiles were calculated using the measurements of the deformation resulting from the successive electrochemical removal of thin layers, It was observed that the sign of the residual stresses in the surface alloy was not changed by one or more intermediate layers.