A.0.4 B.0.5 C.0.55 D.0.6
A.1150-1200℃B.1200-1280℃C.1280-1320℃D.1320-1380℃
A.650℃;6~30% B.700℃;40~70% C.550℃;40~70% D.700℃;5~15%