【摘要】 用光学、电子金相、X射线衍射和膨胀等方法研究了4Cr3Mo2V热作模具钢淬火组织在回火过程中的变化及对常规力学性强的影响。结果表明,随营回火温良的升高,发生马氏体脱溶和M₃C→V₄C₃+Mo₂C+（Cr,Fe）₇C₃→V₄C₃+M₆C 转变,并于750℃发生马氏体板条再结晶,结果强度在590～810℃回火对,冲击韧性在600～820℃回火时,出现峰值,二者随着回火温度升高几乎同向变化。该钢的回火抗力很高,这与其钒高、铬低、钼高有关。增钒强化 V₄C₃的弥敌强化作用;降铬、增钼则使 Cr 与（Cr+Mo+O.7W）原子比降至0.69,从而抑制了稳定性较差的（Cr,Fe）₇C₃析出。更多还原

【Abstract】 Effect of tempering process on quenched structure and mechanical properties of 4Cr3No2Vworking tool steel has been investigated by means of optical microscope,electronic microscope,X-ray diffractometer and dilatometer.Experimental results reveal that the transformations M₃C→V₄C₃+Mo₂C+（Cr,Fe）₇C₃→V₄C₃+M₆C occur in the tempering process.Compared with other hot-working tool steel containing Cr-Mo-V,this steel has higher tempering resistance and structurestability.This is concerned with the increase of V and Mo and the drop of Cr in the alloy,sothe dispersion strengthening of V₄C₃ possessing higher stability is increased and the priclpitati-on tendency of carbide of chromium is weakened.更多还原