42CrMo钢与球墨铸铁焊接工艺研究.docVIP

42CrMo钢与球墨铸铁感应钎焊连接工艺的研究 万幸芝，蒋苗苗2，吴建3，罗云跃4，崔国栋* ( 西南交通大学 材料科学与工程学院, 四川成都 611756) 摘要：以紫铜为焊料，分别在加热时间为10s、20s的两种感应钎焊连接工艺下，将42CrMo钢与球墨铸铁焊接在一起。对连接后的试样进行860℃×30min+260℃盐浴淬火处理。利用金相显微镜、显微硬度计、拉伸试验机等对经两种不同焊接工艺处理所得样品进行微观形貌的观察和熔合区硬度分布及抗拉强度的测试分析。结果表明：随着感应加热时间的延长，焊接口形成良好的冶金结合，复合区无明显紫铜过渡层，热影响区增大，钢组织明显细化，铸铁中石墨部分熔化，但仍保持球状。经不同工艺参数下的样品在等温淬火后均得到综合力学性能良好的下贝氏体组织。随感应加热时间的延长，熔合区硬度分布较为平缓，且抗拉强度明显提高。 关键词：42CrMo钢；球墨铸铁；感应钎焊；等温淬火处理 中国分类号：TG4 文献标识码：J Research of Induction brazing connection process on the 42CrMo steel and Ductile Iron WAN Xing-zhi1, JIANG Miao-miao2，WU Jian3，LUO Yun-yue4， CUI Guo-dong* (Southwest Jiaotong University，Material Science and Engineering institute, Chengdu City 611756, China) Abstract: 42CrMo steel and ductile iron was welded by using the method of induction brazing ,which was heated 10 and 20 seconds with copper as solder . The micro-structural aspects of composite interface, micro-hardness, strength of extension were analyzed with the metallurgical microscopy, micro-hardness tester and tensile testing machine respectively after composite samples were austenitized at 860℃and austempered in salt bath at 260℃. Results show that the samples treated with the longer time of heat preservation have formed a good metallurgical bonding without apparent copper transition layer in the multiple district, but with a bigger heat-affected zone, detailed organization of steel and spherical graphite cast iron with part of the graphite melting. Organization of samples welded in the different parameters is lower bainite with good mechanical properties after isothermal quenching. Hardness distribution is relatively flat in fusion zone. The average tensile strength of the samples is significantly improved. Keywords: 42CrMo steel; ductile iron; induction brazing ; austempering 0 引 言 等温淬火球铁（ADI）最早在20 世纪 70 年代被发现。在随后的时间里,世界上一些国家都在致力于ADI的研究,但各有侧重[1]。国外ADI主要应用于汽车零件[2-4]，如曲轴、连杆、差速器齿轮、发动机支架及车轮毂等。我国ADI产品大致分为三类：普通抗磨件、机械承载构件和高性能、高精度要求的重要构件[5-7]。随着铁路建设的发展，制造高速、舒适化火车是大势所趋，这就