Machinability of duplex stainless steels - A study with focus on the tool wear behaviour

This article presents research done in order to analyse the machinability of duplex stainless steel with coated carbide tools during turning operations. Although duplex stainless steel has existed for about 70 years fairly little work has been published in the area of investigating the different aspects of the machining of these materials. In this research project three different kinds of duplex stainless steels and their properties have been examined. These materials where SAF 2507, SAF 2205 and LDX 2101 which together covers a large part of the duplex stainless steels that are commercially available today. This study focuses on analysing the tool wear behaviour in an attempt to better understand the actual wear patterns during machining, not only the more traditional ones that are in common use today. Some additional tests were also done in order to get a better understanding of the machinability of duplex stainless steel in general. Theories and concepts that are related to the analysing of machinability will be presented, most of which have been previously validated and in use for a long time. Adhesive wear of the cutting tool, in many cases severe, was to some extent found at all different cutting data investigated