Residual stresses in HPDL and ND:YAG laser cladded coatings

Abstract

Applying laser cladded components in expensive machines and engines requires knowledge of residual stresses in order to avoid unexpected failures and further damages. Normally residual stresses induced by laser cladding are highly tensile due to strong thermal gradients. This makes laser coatings susceptible to fatigue and stress corrosion cracking for instance. Laser-induced residual stress state depends on several material and processing parameters. Some of them, for example the effect of subsequent hardening treatment on residual stresses of Stellite 21 coatings on martensitic stainless steel with and without intermediate layers and the effect of heat input were studied here. The residual stresses were measured using X-ray diffraction method.Applying laser cladded components in expensive machines and engines requires knowledge of residual stresses in order to avoid unexpected failures and further damages. Normally residual stresses induced by laser cladding are highly tensile due to strong thermal gradients. This makes laser coatings susceptible to fatigue and stress corrosion cracking for instance. Laser-induced residual stress state depends on several material and processing parameters. Some of them, for example the effect of subsequent hardening treatment on residual stresses of Stellite 21 coatings on martensitic stainless steel with and without intermediate layers and the effect of heat input were studied here. The residual stresses were measured using X-ray diffraction method.