SS400钢对接接头表面纳米化及其对疲劳强度的影响  

Surface Nanocrystaillzation of SS400 Steel Butt Welded Joint and Its Effect on the Fatigue Strength

作　　者：李东[1] 陈怀宁[1] 刘刚[2] 卢柯[2] 林泉洪[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《焊接学报》2002年第2期18-21,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目 (5 0 710 61);973国家计划资助项目 (G19980 615 11)

摘　　要：采用高能喷丸技术对SS4 0 0钢对接接头的表面进行处理 ,利用X射线衍射和透射电镜对表层进行结构表征 ,并测量了对接接头表层硬度、残余应力和疲劳强度的变化。结果表明 ,高能喷丸处理可以在对接接头的表面形成尺寸均匀、晶粒取向呈随机分布的纳米晶组织 ,从而消除了对接接头表层组织的不均匀性 ;纳米结构表层的硬度明显高于心部 ,其内部残余应力为压应力。这种压应力纳米强化层可以明显地提高对接接头的疲劳性能。The welded joint of SS400 stell was treated by high-energy shot peening (HESP) technique, the surface layer was characterized by means of the XRD and TEM, and the changes of hardness, residual stress and fatigue strength were examined. Experimental results showed that nanostructured surface layer might form in the surface layer of welded joint after the HESP treatment, and the crystallographic orientations were nearly random; therefore uniform microstructure could be obtained. The microhardness of the nanostructured surface layer was found to be much higher than that of the sample before the HESP treatment, and the welding residual stresses in this layer became entirely compressive. This kind of nanostructured surface layer with compressive stress could significantly increase the fatigue strength of butt-welded joint.

关 键 词：SS400钢 对接接头 表面纳米化 疲劳强度 

分 类 号：TG441.8[金属学及工艺—焊接]