时效处理对18Ni马氏体时效钢电子束焊缝微观组织和力学性能的影响  

Effect of Aging Treatment on Microstructure and Properties of Electron Beam Welded Joints of 18Ni Steel

作　　者：王艳芳[1] 赵征[2] 

机构地区：[1]陕西工业职业技术学院,咸阳712000 [2]航天科工集团二院210所,西安710065

出　　处：《航空精密制造技术》2014年第3期31-33,共3页Aviation Precision Manufacturing Technology

摘　　要：将18Ni马氏体时效钢电子束焊缝在48℃进行时效处理,时效处理时间分别为1.5、2.5、4.5和6h。采用金相显微镜、扫描电镜观察了不同时效状态下的18Ni马氏体时效钢电子束焊缝的微观组织,测试了不同时效状态下焊接接头的拉伸强度和接头不同区域的硬度值,并用扫描电镜分析了拉伸断口形貌。结果表明,随着时效时间的延长,沉淀粒子粗化引起了过时效,同时马氏体开始逆转变为奥氏体和铁素体,使钢的强度逐渐下降,经480℃,4.5h时效处理后,焊接接头的拉伸强度最高。Microscopy and TEM are used to examine microstructure of 18Ni maraging steel electron beam welded joints under different aging conditions, respectively 1.5h、2.5h、4.5h and 6h at 480 C. The tensile strength and hardness of different aging conditions of the welded joints are tested at room temperature, and SEM is used to analyze fracture appearance. The experimental results show that with the extension of aging time, deposited grains became coarse results in over aging of the welded joints, at the same time austenite intended to transform reversed austenite and ferrite, so the strength of the steel decrease gradually. The most high tensile strength of welded joints is obtained at the aging treatment of 480 C×4.5h.

关 键 词：18NI马氏体时效钢 电子束焊 时效处理 

分 类 号：TG456.3[金属学及工艺—焊接]