强度匹配对核容器用钢A508-Ⅲ焊接接头断裂行为的影响

Effect of Strength Mis-Matching on Fracture Behavior for Nuclear Pressure Vessel Steel A508-Ⅲ Welded Joints

摘要: 针对核容器用钢A508-Ⅲ接头,通过断裂力学试验和有限元数值模拟综合研究强度匹配对接头抗断裂行为的影响,尤其是对热影响区断裂行为的影响。结果表明,选用高匹配焊缝可降低焊缝裂纹试样的裂尖张开应力和应力三轴度,改善焊缝的抗断裂行为;而却使热影响区裂纹试样的裂尖张开应力和应力三轴度升高,对热影响区的抗断裂行为不利,定性地说明了低匹配A508-Ⅲ接头热影响区断裂韧度优于焊缝断裂韧度的试验结果。

Abstract: The effect of strength mis-matching on the fracture behavior of A508 Ⅲ welded joints was analyzed by fracture mechanics test and FE calculation,the fracture behavior for HAZ was emphasized especially.It has been shown that the opening stress and stress triaxiality in the vicinity of crack tip are reduced for weld crack specimen,and increased for HAZ-crack specimen,if the over matching weld is used.In other words,over matching could improve the fracture resistance for weld crack specimen,and deteriorate for HAZ crack specimen.This tendency was confirmed by the test result.