Experimental measurements of residual stresses in welding of steels operating at high temperatures

Abstract

In the paper is described a procedure for experimental measurements of residual stresses during the reparatory hard facing of models made of steel aimed for manufacturing the forging dies. Those steels are aimed for operating at elevated temperatures. They are extremely prone to self-hardening and especially sensitive to localized heat input. Because of those influences appear residual stresses, which, if superseded the yield stress of the base metal, can lead to appearance of deformations and cracks. Numerous methods exist for reducing the residual stresses. Relaxation is used in order to reduce their level and to transfer the martensitic structure into the more favorable ones, while preserving the good mechanical properties of the hard faced layers. Results of presented investigations can be usefully applied in practice, both for selecting the optimal reparation technology and for defining the type and regime of the heat treatment.