一、前言国外的易切削钢生产是从硫系开始的,至今硫系易切削钢仍是易切削钢的主流,此外铅系也占有相当大的比例。然而,由于加硫会降低钢材的机械性能,加铅则会造成环境污染,致使这两种易切削钢在使用上和生产上受到了很大的限制。而硒、碲、铋、锆等易切削钢,则因加入元素价格昂贵,钢的成本增加太多。近些年来已有一些国家开展了对钙易切削钢和钙与其他易切元素复合的易切 I. Introduction Foreign free-cutting steel production starts from the sulfur system. Up to now, the sulfur-based free-cutting steel is still the mainstream of free-cutting steel. In addition, the lead system also occupies a considerable proportion. However, since sulfur addition can reduce the mechanical properties of steel, adding lead will cause environmental pollution, resulting in the use of these two types of free-cutting steel and the production has been greatly limited. The selenium, tellurium, bismuth, zirconium and other free-cutting steel, then by adding the element price is expensive, the cost of steel increased too much. In recent years, some countries have carried out on the easy-cutting of calcium-free cutting steel and calcium complexed with other easy-to-cut elements