摘要
以紫铜为焊料,分别在加热时间为10及20 s的两种感应钎焊工艺下,将42CrMo钢与球墨铸铁焊接在一起。对连接后的试样进行860℃×30 min+260℃盐浴处理。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,铸铁中石墨部分分解,细化了球状石墨。经不同工艺参数下焊接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,复合区硬度分布较为平缓,且抗拉强度明显提高。
42CrMo steel and ductile iron were welded by using induction brazing with copper as solder, which was heated for 10 s and 20 s. The microstructure of the weld joint was analyzed by microscopy. The microhardness and tensile properties of the weld fusion-zone were tested by microhardness tester and tensile testing machine, respectively. The results show that with increasing the induction heating time, the samples tends to form a good metallurgical bonding without apparent copper transition layer in the multiple districts, the heat-affected zone becomes larger, the microstructure gets refiner, and the part of the graphite in the spherical graphite cast iron gets decomposing but keeping the certain shape. The lower bainite with good mechanical properties can be obtained after isothermal quenching. The hardness distribution is relatively fiat, while the average tensile strength of the samples is significantly improved in the composite section.
出处
《热加工工艺》
CSCD
北大核心
2014年第3期34-36,共3页
Hot Working Technology
基金
西南交通大学个性化实验项目
西南交通大学大学生科研训练计划项目(121010)
