我厂最近制造一批12鋼的鑽头和拉刀(原来用合金鋼制造),尺寸是Φ30～50×350～500,要求硬度Rc60～64。用分級淬火(160～180℃鹽)而后进行校直,这样大截面的工具根本就达不到硬度要求。如果用水淬油冷方法,淬火后工具沒法进行校直;虽然在180℃回火后可以热压,但很容易压断。針对着这种情况,我們混合采用了分組淬火和双液淬火(水淬油冷)的 Our factory recently made a number of 12 steel drill bits and broaches (originally made of alloy steel), the size is Φ30 ~ 50 × 350 ~ 500, the required hardness Rc60 ~ 64. With the classification of quenching (160 ~ 180 ℃ salt) and then straightening, so that the large cross-section of the tool simply does not meet the hardness requirements. If the water quenching oil cooling method, the tool can not be quenched after straightening; Although after 180 ℃ tempering can be hot, but it is easy to crush. In response to this situation, we used a mixture of group quenching and dual-liquid quenching (water quenching oil cold)