Effects of Si and Cr on Complete Decarburization Behavior of High Carbon Steels in Atmosphere of 2 vol. O2

摘要

The effects of chemical compositions,especially silicon and chromium contents,on the complete decar-burization behaviors of steels in atmosphere of 2 vol.% O2 and 98 vol.% N2 were investigated by using a simultane-ous thermal analyzer.Complete decarburization was observed at both 750 and 800 ℃ for 60Si2MnA steel,while 750 ℃only for 92A steel.For GCr15 steel,no decarburization was found at 750 or 800 ℃,and only partial decarburization was observed at 850 ℃.It indicates that silicon promotes while chromium prevents the complete decarburization of steels in atmosphere with 2 vol.% O2 .The main reason is that silicon increases while chromium reduces the equilib-rium concentration of ferrite at the interface of ferrite and austenite,which results in the complete decarburization.