中文摘要：

对经镦抜锻造的4Cr5W2VSi模具钢进行标准退火和调质处理,沿拔长方向（纵向）和垂直于拔长方向（横向）切取试样进行组织分析、拉伸试验、冲击试验和硬度测试,研究其组织和力学性能。结果表明：退火态组织为粒状珠光体＋少量共晶碳化物,调质态组织为回火托氏体＋少量共晶碳化物;两种状态均存在偏析,调质处理不能改善带状偏析,带状偏析降低了力学性能。退火态试样的屈服强度、抗拉强度比H13钢提高了45 MPa、90 MPa,塑性略有下降。退火态试样纵向冲击吸收能量为94.3 J,高于横向试样（51 J）,存在各向异性;调质态试样纵向和横向冲击吸收能量分别为18.3 J和16.7 J,不存在各向异性,均为脆性断裂。调质态试样的硬度为退火态的3倍左右,其硬度提高是因为生成了脆性托氏体相及二次硬化作用。

英文摘要：

Upset and stretched 4Cr5W2 VSi die steel was annealed,and quenched and tempered. Microstructure and mechanical properties of the specimens were analyzed by microstructure analysis,tensile test,impact test and hardness test along the horizontal direction and vertical direction. The results show that the annealed state microstructure is spheroidal pearlite and a small amount of eutectic carbide,and queched and tempered state microstructure is tempered troostite and a small amount of eutectic carbides. There exsists segregation in the two kinds state. The zonal segregation can not be improved by quenching and tempering,that reduces the mechanical properties of the steel. Compared with H13 steel,the yield strength and tensile strength of annealed samples increase by 45 MPa,90 MPa,and the plasticity decrease slightly.The longitudinal and transverse impact absorbed energy of annealed samples is 94. 3 J and 51 J respectively,there exsis anisotropy. The longitudinal and transverse impact absorbed energy of quenched and tempered samples is 18. 3 J and 16. 7 J,respectively,there is no anisotropy,and belong to brittle fracture. The hardness of quenched and tempered state is about three times of that of annealed steel,that is resulted in troostite and secondary hardening.