摘要
采用辊压加载的方式在16Mn钢焊接接头处形成微量塑性预应变,研究辊压变形后材料本身的疲劳和力学性能变化(不计表面效应)。利用SEM观察疲劳断口和TEM观察位错形貌。试验结果表明,虽然金属辊压变形后的强度和硬度有所提高,但疲劳极限明显降低。断口呈完全的脆性状态,位错大量增殖并表现为胞状亚结构。分析认为,辊压后材料中位错的特殊结构和材料内部所形成的损伤累积是疲劳性能下降的主要原因。
The fatigue and mechanical properties of 16Mr steel welded joint by rolled prestrain have been determined with the rotating bending specimens. The fractograph and dislocation morphology were observed by means of SEM and TEM. The experimental results indicate that the fatigue limit of the material by rolled prestrain was apparently reduced although its strength and hardness were increased. The fatigue fractograph of the material with microprestain showed entire embrittle feature; and the dislocations were mostly multiplicated and displayed cell substructure. It is considered that special structure of the dislocation and damage accumulation induced by rolled were main factors to make the fatigue strength of the welded joint reduced after rolled prestrain.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
1992年第3期193-197,共5页
Transactions of The China Welding Institution
关键词
辊压预应变
焊接接头
疲劳
rolled prestrain
welded joint
fatigue
