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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。
The as-forged 4Cr5W2VSi die steel was subjected to standard annealing and quenching and tempering treatments. The samples were cut along the length and length directions (vertical direction) and perpendicular to the direction of elongation (transverse direction) for microstructure analysis, tensile test, impact test and hardness test, Study its organization and mechanical properties. The results show that: the annealed microstructure is granular pearlite + a small amount of eutectic carbide, tempering the tempering of the microstructure is a small amount of eutectic carbide; segregation exist in both conditions, quenching and tempering can not improve the ribbon segregation, Strip segregation reduces mechanical properties. The yield strength and tensile strength of annealed samples increased by 45 MPa and 90 MPa, respectively, compared with that of H13 steel. The plasticity decreased slightly. The longitudinal shock absorption energy of annealed samples is 94.3 J, which is higher than that of the transverse samples (51 J), and the anisotropy exists in the samples. The longitudinal and transverse impact energy of quenched and tempered samples are 18.3 J and 16.7 J, respectively. Heterosexual, are brittle fracture. The hardness of the quenched and tempered sample is about 3 times that of the annealed sample. The hardness of the sample increases due to the formation of brittle and austenite phase and secondary hardening.