A.BT100 B.KT200 C.HT300 D.QT400-18
A.0.04%~0.25% B.0.25%~0.6% C.0.6%~1.5% D.1.5%~2.0%
A.<0.04% B.0.04%~0.25% C.0.25%~0.6% D.0.6%~2.0%