Fe_3Al合金与Q235钢扩散焊界面的析出相  

PRECIPITATE AT DIFFUSION-BONDED INTERFACE BETWEEN Fe_3Al ALLOY AND STEEL Q235

作　　者：王娟[1] 李亚江[1] 马海军[1] 

机构地区：[1]山东大学材料液态结构及其遗传性教育部重点实验室,济南250061

出　　处：《金属学报》2005年第9期989-993,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50375088;山东省自然科学基金项目Y2003F05资助

摘　　要：采用扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)和电子探针(EPMA)对Fe3Al/Q235扩散焊界面的析出相形貌进行观察和成分测定,研究微观析出相的形成以及工艺参数(T,t,P)的影响.结果表明,Fe3Al/Q235扩散焊界面靠近Fe3Al一侧形成FeAl(Cr)析出相,是引起扩散焊接头脆性断裂的关键.扩散焊温度T、保温时间t与析出相区宽度y符合抛物线规律:y2=3.5(t-to)exp[-5.6×104/(RT)].在降低加热温度和保温时间的条件下,增加焊接压力可促进Fe3Al/Q235界面原子的扩散,避免脆性析出相的形成,保证Fe3Al/Q235扩散焊接头的性能.Morphology, structure and chemical composition of the precipitate at Fe3Al/Q235 diffusion-bonded interface were studied by means of scanning electron microscope （SEM）, energy dispersive spectrum （EDS）, X-ray diffractometer （XRD） and electron probe micro-analysis （EPMA）. The formation of the precipitate and the effect of technological parameters on the precipitate were also investigated. The results indicate that FeAI（Cr） was formed in the Fe3Al side of the Fe3Al/Q235 diffusionbonded interface, which is the key to cause brittle fracture of the Fe3Al/Q235 bonded joint. The relation between the formation and growth of FeAl（Cr） and bonding parameters obeys the parabolic law, y^2 = 3.5（t - t0）exp[-5.6 × 10^4/（RT）]. So in order to avoid the formation of the precipitate and to ensure the performance of the Fe3Al/Q235 bonded joint, it is necessary to increase pressure for accelerating the atom diffusion at the interface with lower heating temperature and shorter bonding time.

关 键 词：FE3AL合金 Q235钢 扩散焊 析出相 

分 类 号：TG401[金属学及工艺—焊接]