主管道用材中低加载速率下常温断裂性能研究

Study on Room Temperature Fracture Behavior of Main Pipeline Materials at Medium and Low Loading Rate

核电厂主管道在长期服役下,母材及焊接处可能出现裂纹,需要对主管道材料及焊接材料在中低加载速率下的断裂性能进行研究,避免主管道在强地震冲击下可能出现的双端剪切断裂。基于Instron VHS高速材料试验机,开发了一套材料在中低加载速率下的断裂性能测试方法,测量了核电厂主管道材料控氮00Cr17Ni12Mo2及焊接材料OK Tigrod 316L在0.5 m/s加载速率以内的常温断裂性能。结果表明,常温下核电厂主管道材料控氮00Cr17Ni12Mo2在0.5 m/s冲击速率以内并不启裂,焊接材料OK Tigrod 316L在0.5 m/s加载速率以内的断裂韧性并未出现明显的规律性变化。

Cracks may occur at the base metal and welding joint of the main pipeline of a nuclear power plant(NPP)during the long-term service.Therefore,it is necessary to study the fracture behavior of the main pipeline material and welding material at medium and low loading rate to avoid the possible double-ended guillotine break of the main pipeline under strong earthquake impact.This study,relying on the Instron VHS high strain rate testing machine for materials,develops a set of testing method for fracture behavior of materials at medium and low loading rate,which in turn is used to measure the room temperature fracture behaviors of main pipeline nitrogen-containing material(00Cr17Ni12Mo2)and welding material(OK Tigrod 316L)within the loading rate of 0.5 m/s in a NPP.As observed from the results,under the room temperature,the main pipeline nitrogen-containing material(00Cr17Ni12Mo2)shows no crack initiation within the impact rate of 0.5 m/s,and the fracture toughness of the welding material(OK Tigrod 316L)indicates no obvious regular change within the loading rate of 0.5 m/s.