为研究N5单晶含取向差TLP接头组织和断裂机理，制备了有取向差和无取向差的接头。对接头微观组织进行SEM检测，跨焊缝进行了EBSD检测，并对接头进行了高温持久拉断试验。结果表明，两侧母材存在10°取向差时焊缝中心无法实现单晶化而形成晶界，晶界处元素偏聚导致在降温过程中形成碳化物和硼化物的第2相粒子；断口分析表明B接头以准解理形式断裂，裂纹起源于第2相粒子。%Joints with or without misorienta-tion are prepared in order to discuss the microstructure and fracture mechanism of a joint that with a misorienta-tion. Microstructure is SEM tested, orientation data are observed by the method of EBSD and the high temperature creep rupture tests are carried out. Results show that crys-tal boundary can be found in the center line when there is a 10 degree misorientation between the two parts of base metal. Carbide and boride are formed by the effect of high energy boundary and element segregation. Fracture analy-sis reveals that cracks generate from the second phase par-ticle and the joint fractures in the form of quasi-cleavage fracture.
展开▼
