摘要
采用填丝钨极氩弧焊(TIG)对Fe3Al与18-8钢进行焊接,用扫描电镜和电子探针分析Fe3Al/18-8钢接头的微观裂纹及断口特征,用透射电镜分析接头区的位错形态.结果表明,Fe3Al/18-8钢接头裂纹起源于Fe3Al侧熔合区,断口形态以穿晶解理断裂为主,解理面上分布着由解理台阶组成的河流花样.焊缝区的断口由部分剪切韧窝构成,焊缝区的韧性优于熔合区.Fe3Al侧熔合区分布有不同密度的位错,是Fe3Al/18-8钢接头潜在裂纹源.微裂纹在应力作用下向Fe3Al热影响区扩展,与主裂纹汇合后,发生剪切断裂.
Fe3Al and 18-8 steel dissimilar materials were welded by tungsten inert gas arc welding (TIG) with filler metal. The cracking and fracture characterization of Fe3Al/18-8 joint were analyzed by mans of SEM and EPMA. The dislocation morphology was investigated via TEM. The results indicated that the cracks initiated in the fusion zone of Fe3Al side. The fracture was mainly in trans-granular cleavage mode and there distributed obvious rivers patterns composed of cleavage steps. The weld zone was composed of partial dimples,indicating the better toughness than that of the fusion zone. The dislocations of different density were distributed in the fusion zone of Fe3Al side,which was the potential cracking of the welding joint. The micro-cracks propagated to Fe3Al HAZ until rupture when the local stress was larger than critical stress.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2010年第7期1-4,共4页
Transactions of The China Welding Institution
基金
国家自然科学基金(50874069)
山东省自然科学基金(Y2007F54)
山东省科技发展计划项目(2007GG10004016)
