【摘要】 用示波冲击法测定了在冲击载荷下,淬回火态42CrMo钢的载荷-挠度曲线,并将冲击总功分成裂纹萌生功和裂纹扩展功;研究了回火温度对42CrMo钢回火组织与冲击韧性的影响。结果表明42CrMo钢在回火过程中,随回火温度升高,弹性功基本不变,裂纹萌生功略有升高,而裂纹扩展功迅速增加,42CrMo钢对缺口敏感,随回火温度升高,缺口敏感性降低,淬火态42CrMo钢经500—590℃回火,其组织由板条马氏体和条状及粒状θ-Fe₃C组成;冲击断口为准解理与韧窝混合断裂,随回火温度升高,韧窝增多,准解理减少。更多还原

【Abstract】 The elastic energy and the cracking initiation and propagation energy of quenched and tempered 42CrMo steels were measured by oscillographic impact method. The effect of tempering temperatures on the structure and impact toughness of 42CrMo steels was also investigated. Results show that: with the increase of tempering temperature, the elastic energy will not change,however,the cracking initiation energy increases slightly and the cracking propagation energy increases rapidly. The tested steels possess notch sensitivity. With the increase of tempering temperature, the notch sensitivity of 42CrMo steel decreases. After 500-590℃ tempering, all the microstructures of 42CrMo steels consist of lath martensite and bar/granular cementite carbides. The impact fracture surface is composed by quasi-cleavage and dimple pattern. With the increase of tempering temperature,dimple areas increase.更多还原