Application of Rare Earth Elements in Lead-Free “Green Steel”

Abstract

In this paper, free cutting austenitic stainless steel containing rare earths was investigated. The machinability tests were conducted by using an YDC-Ⅲ85 dynamometer on a CA6164 lathe. The metallurgical properties, machinability and mechanical properties of lead-free “green steel” were compared with those of the conventional austenitic stainless steel. The results have shown that globular shape MnS inclusions were obtained, and rare earths elements were enwrapped in sulfides. The machinability of austenitic stainless steel containing sulfur and rare earth was improved. A satisfactory mechanical property was attributed to the formation of globular shape sulfides. Lead can be replaced by sulfur and rare earth, and environmentally undesirable substances can be eliminated.