渗碳热处理后18CrNiMo7–6合金钢表面变质层J–C损伤失效参数研究  

Study on J–C Failure Parameters of Surface-Modified Layer of 18CrNiMo7–6 Alloy Steel After Carburizing Heat Treatment

作　　者：陈雷 张建伟[2] 王冰冰[2] CHEN Lei;ZHANG Jianwei;WANG Bingbing(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China;School of Mechanics and Safety Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学机械与动力工程学院,郑州450001 [2]郑州大学力学与安全工程学院,郑州450001

出　　处：《航空制造技术》2024年第18期66-72,共7页Aeronautical Manufacturing Technology

基　　金：国家自然科学基金(12202424,U1804254);河南省重大科技专项(201400211200)。

摘　　要：合金钢在经过渗碳热处理后会在表面形成变质层。在表面变质层内,材料的力学性能沿深度方向发生变化。针对渗碳热处理后的18CrNiMo7-6合金钢的表面变质层,提出了确定Johnson-Cook损伤参数分层测试方法。通过对材料变质层进行分层线切割,得到不同变质层深度下的薄板试样;为获得不同应力三轴度下的拉伸结果,预制了不同断裂方向的拉伸剪切试样,通过试验与仿真相结合的方法,确定了考虑应变累积效应的应力三轴度并测定了材料失效应变与应力三轴度的关系;采用宽脉冲拉伸系统测定了拉伸试样的失效应变与应变率的关系。研究结果表明,同一层材料的失效应变随应力三轴度的增大而减小,在同一应力三轴度水平下,失效应变随层深增大而增大;不同层深处的试样均具有明显的应变率弱化效应,且在同一应变率水平下,失效应变随层深增大而增大;基于测量参数的拉伸过程数值仿真与试验数据的对比验证了所测定参数的准确性。After carburizing heat treatment,a modified layer forms on the surface of alloy steel,within which the mechanical properties of the material change along the depth direction.In this paper,a delamination test method for measuring Johnson–Cook damage parameters is proposed for the surface modification layer of 18CrNiMo7–6 alloy steel after carburizing heat treatment.Thin plate samples with different metamorphic layer depths were obtained by wireelectrode cutting from the modified layer of the material.In order to obtain tensile results under different stress triaxiality,this work prefabricated tensile shear specimens with different fracture directions,and determined the stress triaxiality considering the cumulative effect of strain through combination of experimental and simulation methods.In addition,the relationship between material failure strain and stress triaxiality was measured and the relationship between failure strain and strain rate of tensile specimens was measured using a wide pulse tensile system.The results show that the failure strain of a material in the same layer decreases with the increase of stress triaxiality,and at the same stress triaxiality level,the failure strain increases with the increase of depth.The samples at different layer depths had significant strain rate weakening effects,and at the same strain rate level,the failure strain increased with the increase of layer depth.Based on the measured parameters,a numerical simulation of the tensile process was conducted and compared with the experiment to verify the accuracy of the parameters measured in this paper.

关 键 词：渗碳热处理 18CrNiMo7-6合金钢 表面变质层 Johnson-Cook损伤模型 数字图像相关技术 

分 类 号：V252[一般工业技术—材料科学与工程]