C0.32~0.45,
Si0.80~1.20,
Mn0.20~0.50,
Cr4.75~5.50,
Mo1.10~1.75,
V0.80~1.20,
p小于等于0.030,
S小于等于0.030;
(交货状态:布氏硬度HBW10/3000(小于等于235))
淬火:790度+-15度预热
1000度(盐浴)或1010度(炉控气氛)+-6度加热
保温5~15min空冷
550度+-6度回火退火、热加工;