Randschichteigenspannungen durch mechanisches Schleifen bei hochfesten Federstählen

Oil tempered steel, like the high strength spring steel 54SiCr6 (1.7102), is mainly used for helical springs. To enlarge the contact area between spring and adjacent parts, the spring tail is often flat‐grinded. Due to wire‐drawing process residual stress is already existing before spring manufacturing. The spring manufacturing process contains several sequenced steps like winding, even grinding and shot peening. All of these steps cause additional or influence the existing residual stress in wire. The knowledge of these mechanisms and the level of residual stress is mandatory for design of application and its operation. Grinding processes in general has major influence to the residual stress level. In fact the choice of grinding parameter is essential for the stress height. In general: thermal effects while grinding cause basically tensile stress, mechanical effects cause basically pressure stress. Presented investigation shows the qualitative influence of several grinding parameters like infeed, conventional or synchronized grinding operation mode and the optional usage of cooling lubricant. The superposition of grinding‐based residual stress with different residual stress depends not only on the stress‐height but also on the characteristic. Therefore universally statements are not available.