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M_3C→V_4C_3+Mo_2C+(Cr,Fe)_7C_3→V_4C_3+M_6C 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 V_4C_3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)_7C_3析出。
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 M_3C→V_4C_3+Mo_2C+(Cr,Fe)_7C_3→V_4C_3+M_6C 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 V_4C_3 possessing higher stability is increased and the priclpitati-on tendency of carbide of chromium is weakened.
出处
《钢铁》
CAS
CSCD
北大核心
1990年第9期40-45,共6页
Iron and Steel
