基于声发射参数的35CrMo钢断裂韧度研究  

Study on fracture toughness of 35CrMo steel based on acoustic emission parameters

作　　者：郭文博 石健[1] GUO Wen-bo;SHI Jian(School of Mechanical Engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学机电工程学院,四川成都610500

出　　处：《塑性工程学报》2022年第3期174-181,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52078441)。

摘　　要：为了测量35CrMo钢的断裂韧度,使用声发射仪和红外热像仪采集了35CrMo钢准静态断裂韧度试验过程中的声发射信号和红外热像,分析了CT试样断裂过程中的载荷-COD曲线、声发射特征参数和表面温度变化,并与ANSYS有限元计算的裂纹尖端区域的等效塑性应变进行了比较。结果表明,35CrMo钢的断裂过程分为弹性变形阶段、裂纹萌生阶段和裂纹不稳定扩展阶段;通过声发射累计能量计数得到35CrMo钢的断裂韧度为40.22 MPa·m^(1/2),小于ASTM E399—19计算的断裂韧度63.74 MPa·m^(1/2),相对误差为36.90%;通过比较红外热像发现断裂过程中试件表面没有发生明显的温度变化;通过声发射参数的变化趋势、红外热像及等效塑性应变分布的比较,验证了使用声发射参数估算35CrMo钢断裂韧度的合理性。To measure the fracture toughness of 35 CrMo steel,acoustic emission signals and infrared thermal images of 35 CrMo steel during quasi-static fracture toughness test were collected by acoustic emission instrument and infrared thermal imager.The load-COD curves,acoustic emission characteristic parameters and surface temperature changes of CT specimens during fracture process were analyzed,and the equivalent plastic strain in the crack tip region calculated by ANSYS finite element was compared.The results show that the fracture process of 35 CrMo steel is divided into elastic deformation stage,crack initiation stage and unstable crack propagation stage.The fracture toughness of 35 CrMo steel is 40.22 MPa·m^(1/2) by acoustic emission cumulative energy counts which is less than 63.74 MPa·m^(1/2) calculated by ASTM E399—19,and the relative error is 36.90%.It is found that there is no obvions temperature change on specimen surface during fracture process by comparing infrared thermal images.The rationality of fracture toughness of 35 CrMo steel estimated using acoustic emission parameters is verified by comparing the changing trend of acoustic emission parameters,infrared thermal images and equivalent plastic strain distribution.

关 键 词：35CRMO钢 断裂韧度 声发射 红外热像 塑性应变 

分 类 号：TG115.5[金属学及工艺—物理冶金]