Abstract: in this paper, a profound study has been made on the formation mechanism of workpiece burnt surface and various chemical and physical changes of burnt surface layers during creep feed grinding of nickel base cast superalloy K417 by means of some advanced instruments such as SEM, EPA, XPS, etc. According to conventional criterion for grinding burn. Based on experimental facts, it is pointed out that only burning with purple black probably does substantive damage to the service life of parts considering the native characteristics of superalloys.

Key words: creep feed grinding, grinding burn, nickel base cast superalloy