Wear mechanisms of cemented carbide tools in dry cutting of precipitation hardening semi-austenitic stainless steels

Dry turning tests were carried out on Cr12Mn5Ni4Mo3Al precipitation hardening semi-austenitic stainless steels with two kinds of carbide tools (WC/Co and WC/TiC/Co). The tool wear, the cutting forces, and the cutting temperature were measured. The element diffusion from the Cr12Mn5Ni4Mo3Al stainless steel to carbide tools (vice versa) at temperatures up to 600 °C was examined. The morphology of the diffusion couples was detected by SEM. Results showed that WC/TiC/Co carbide tools are more suitable for the machining of Cr12Mn5Ni4Mo3Al stainless steel. The flank wear, the cutting forces, and the cutting temperature of WC/TiC/Co tool are smaller than that of the WC/Co one under the same test conditions. There was evidence of element diffusion from the tool rake face to the adhering chip (vice versa), which leads to the tool element loss and microstructure change. The wear mechanisms of the carbide tools in dry machining of Cr12Mn5Ni4Mo3Al stainless steel were mainly abrasive wear, adhesion and diffusion wear.

Research highlights▶ Dry turning tests were carried out on Cr12Mn5Ni4Mo3Al precipitation hardening semi-austenitic stainless steels with two kinds of carbide tools. ▶ Results showed that the WC/TiC/Co carbide tools are more suitable for the machining of Cr12Mn5Ni4Mo3Al stainless steel, and have higher flank wear resistance over the WC/Co one. ▶ There was evidence of diffusion of W and Co elements of the carbide tool to the Cr12Mn5Ni4Mo3Al stainless steels, and Fe, Cr, Mn, and Mo of the Cr12Mn5Ni4Mo3Al stainless steel to the carbide tool when the cutting temperature is above 400 °C. ▶ The wear mechanisms of the carbide tools in dry machining of Cr12Mn5Ni4Mo3Al stainless steel were mainly abrasive wear, adhesion and diffusion wear.