A New Pb-Free Machinable Austenitic Stainless Steel

The machinability tests were conducted by using various process parameters on a CA6164 lathe with a dynamometer. The metallurgical properties, machinability and mechanical properties of the developed alloy were compared with those of an austenite stainless steel 1Cr18Ni9Ti. The results show that the machinability of the austenitic stainless steels with free cutting additives is much better than that of 1Cr18Ni9Ti. This is attributed to the existence of machinable additives. The inclusions might be composed of MnS. Sulfur and copper addition contributes to the improvement of the machinability of austenitic stainless steel. Bismuth is an important factor to improve the machinability of austenitic stainless steel, and it has a distinct advantage over lead. The mechanical properties of the free cutting austenitic stainless steel are similar to those of 1Cr18Ni9Ti. A new Pb-free austenitic stainless steel with high machinability as well as satisfactory mechanical properties has been developed.