材料：优质合金钢                                     热处理
       (1) 38CrMoAlA (JIS SACM645)             渗氮处理
       (2) 42CrMo (AISI 4140)                        电镀硬铬层
       (3) Cr12MoV (JIS SKD-11)                   高频淬火 
       (4) 4Cr5MoSiV1 (JIS SKD-61)               喷涂双金属合金层