摘要
对42CrMo钢进行液氮冷却磨削淬火试验,改变液氮喷射压力和位置控制淬火时的过冷度和淬火温度,测试磨削淬火后的淬硬层组织及厚度,测量磨削表面的粗糙度。结果表明:当喷口距磨削面的距离S_k为(10~20)mm时表层生成了以马氏体为主的淬硬层组织,S_k为10 mm时淬硬层为针状的马氏体组织,S_k为20 mm时喷氮压力对淬硬层影响更明显,表现为细小的针状马氏体、粗大的板条状马氏体及二者的混合体,说明喷射位置对能否发生淬火及淬火后组织性能具有重要影响;淬硬层厚度受喷射压力pg和喷射距离S_k的共同作用,pg为0.6 MPa,S_k为10 mm时淬硬层厚度达3 mm,pg为0.2MPa,S_k为20 mm时淬硬层厚度约为2 mm;喷射位置S_k由10 mm增大至20 mm淬火表面粗糙度增大,液氮喷射压力pg的变化对表面粗糙度影响不明显。
Grind-hardening experiments with liquid nitrogen cooling were carried out on 42 CrMo steel by changing the injection pressure and the location of liquid nitrogen to control the supercooling and quenching temperature during quenching.The structure and thickness of hardened layer after grind-hardening were tested,and the roughness of grinding surface was measured.The result shows that when the distance Skbetween spout and grinding surface is from 10 mm to 20 mm,there exist some hardened layer structures based on martensite at some certain depth of the surfaces.When Sk=20 mm,the nitrogen injection pressure has more obvious impact on hardened layer,the microstructures are fine needle martensite,coarse lamellar martensite and the mixture of both.Both the injection pressure pgand the distance Skhave influence on the thickness of hardened layer,the thickness can reach 3 mm when the pgis 0.6 MPa and the Skis 10 mm,and about 2 mm when the pgis 0.2 MPa and the Skis 20 mm.With Skincreasing from 10 mm to 20 mm,the roughness of grinding surface increases,but the impact caused by the change of liquid nitrogen injection pressure is not obvious.
作者
刘克铭
沈达
王宝来
朱凌
赵庆鹏
LIU Keming;SHEN Da;WANG Baolai;ZHU Ling;ZHAO Qingpeng(College of Mechanical Engineering,Liaoning Technical University,Fuxin 123000,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2019年第5期19-23,共5页
Ordnance Material Science and Engineering
基金
国家自然科学基金(51405213)
关键词
液氮冷却
磨削淬火
淬硬层
显微硬度
马氏体组织
liquid nitrogen cooling
grind-hardening
hardening layer
micro-hardness
martensitic structure
作者简介
刘克铭,男,博士,副教授;主要从事机械制造研究,发表论文40余篇。E-mail:88399633@qq.com;通信作者:沈达,男,硕士;主要从事机械制造研究。E-mail:1812456304@qq.com。
