Characterization of shot peened components by X-ray diffraction: A method on its way from the laboratory into industrial product development

A main beneficial effect of shot peening is the creation of compressive residual stresses. Thus, reliable and accurate methods for determining residual stresses are needed to allow controlling the process, verifying models and assessing strength increasing mechanisms. Since a long time X-ray diffraction (XRD) has been the choice method for basic residual stress investigations. Due to missing a norm or practice guides being internationally accepted, this method has been hindered to be also the first choice in case of acceptance tests. This gap is no going to be closed. A European standard for residual stress determination using X-ray diffraction has been evaluated by an expert group and will be available shortly. This paper summarizes the basic principles of the method, sketches the range of applications covered by the norm and explains some of the limiting cases defined by the norm. Special emphasis is given to the relevance of the norm for residual stress investigations on shot peened materials.