A.550℃~Ms B.450℃~Ms C.350℃~Ms D.250℃~Ms
A.650~550℃ B.650~350℃ C.550~350℃ D.550~450℃
A.0.1%~0.5% B.0.2%~1% C.0.3%~1.2% D.0.5%~1%