摘要
对H13钢进行电火花加工,研究了电火花加工对其微观形貌、物相组成、残余应力、显微硬度和冲击性能的影响。结果表明:电火花加工后H13钢表面出现熔融颗粒、陨石坑、孔洞、微裂纹等缺陷,截面分为白亮层、热影响区、回火区和基体;白亮层中存在柱状晶、柱状树枝晶、等轴晶、共晶组织等,显微组织包括马氏体、残余奥氏体、Fe_(3)C、Fe_(7)C_(3)、(Cr,Fe)_(7)C_(3)、Fe_(0.3)Mn_(2.7)C等相;相比基体,白亮层中的碳元素和残余奥氏体含量增加;电火花加工后H13钢表层的残余应力和显微硬度均高于基体,且随着距表面距离增加,均先增大后减小,最大分别为575 MPa、647.3 HV;电火花加工后H13钢的冲击功比磨削加工后下降了35.56%,冲击断口出现大量撕裂棱,还有韧窝、解理面、大尺寸剥离面,为准解理断裂。
H13 steel was processed by electrical discharge machining.The effects of electrical discharge machining on the microstructure,phase composition,residual stress,microhardness and impact properties of H13 steel were studied.The results show that the surface of H13 steel after electrical discharge machining had some defects,such as molten particle spheres,craters,holes and micro-cracks.The cross-section was divided into white bright layer,heat affected zone,annealing zone and matrix.There were columnar crystals,columnar dendrites,isaemic crystals and eutectic structures in the white bright layer,and the microstructure included martensite,residual austenite,Fe_(3)C,Fe_(7)C_(3),(Cr,Fe)_(7)C_(3)and Fe_(0.3)Mn_(2.7)C,etc.Compared with the matrix,the content of carbon and residual austenite increased.The residual stress and microhardness of H13 steel after electrical discharge machining were higher than those of the matrix,and increased first and then decreased,and the maximum values were 575 MPa and 647.3 HV,respectively.After electrical discharge machining,the impact energy of H13 steel was reduced by 35.56%compared with that after grinding machining;there were a lot of tearing edges,dimples,cleavage planes and large scale stripping planes on the impact fracture,and the fracture had quasi-cleavage fracture characteristics.
作者
杨会凯
吴晓春(导师)
左鹏鹏
YANG Huikai;WU Xiaochun;ZUO Pengpeng(State Key Laboratory of Advanced Special Steel,School of Material Science and Engineering,Shanghai University,Shanghai 200444,China;Shangda Xinlun Material and Technology(Guangdong)Co.,Ltd.,Zhaoqing 526105,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第2期41-48,共8页
Materials For Mechanical Engineering
基金
广东省重点领域研发计划项目(2020B010184002)。
关键词
H13钢
电火花加工
表面完整性
白亮层
显微硬度
冲击功
H13 steel
electrical discharge machining
surface integrity
white bright layer
microhardness
impact energy
