Turning of high strength, austenitic stainless steels

High interstitial austenitic stainless CrMn steels are characterised by significantly increased work hardening ability and strength compared with conventional CrNi austenites, yet maintaining very high ductility and toughness. The machining of high interstitial CrMnCN steels is challenging in terms of process stability and economic efficiency. In this context, unfavourable chip forms, high thermomechanical loads and the superposition of different wear mechanisms in particular lead to challenges in turning operations. In the following article, different lubricant strategies are analysed for machining of CrMnN and CrMnCN austenitic stainless steels regarding chip form, mechanical tool loads and wear. Furthermore, the workpiece properties are considered with regard to surface roughness and microstructural changes.