Fracture toughness and fracture behavior of SA508-Ⅲ steel at different temperatures  

作　　者：Jia-hua Liu Lei Wang Yang Liu Xiu Song Jiong Luo Dan Yuan 

机构地区：[1]Key Laboratory for Anisotropy and Texture of Materials, Northeastern University

出　　处：《International Journal of Minerals,Metallurgy and Materials》2014年第12期1187-1195,共9页矿物冶金与材料学报（英文版）

基　　金：financially supported by the Major State Basic Research Development Program of China (No. 2011CB610506);the National Natural Science Foundation of China (Nos. 51371044 and 51171039);the Fundamental Research Fund for the Central Universities of China (No. N130410001)

摘　　要：The fracture toughness of SA508-Ⅲ steel was studied in the temperature range from room temperature to 320℃ using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the conditional fracture toughness （JQ） of the steel first decreased and then increased with increasing test temperature. The maximum and minimum values of do were 517.4 kJ/m^2 at 25℃ and 304.5 kJ/m^2 at 180℃, respectively. Dynamic strain aging （DSA） was also observed to occur when the temperature exceeded 260℃ with a certain strain rate. Both the dislocation density and the number of small dislocation cells effectively increased because of the occurrence of DSA; as a consequence, crack propagation was more strongly inhibited in the steel. Simultaneously, an increasing number of fine carbides precipitated under high stress at temperatures greater than 260℃. Thus, the deformation resistance of the steel was improved and the Jo was enhanced.The fracture toughness of SA508-Ⅲ steel was studied in the temperature range from room temperature to 320℃ using the J-integral method. The fracture behavior of the steel was also investigated. It was found that the conditional fracture toughness （JQ） of the steel first decreased and then increased with increasing test temperature. The maximum and minimum values of do were 517.4 kJ/m^2 at 25℃ and 304.5 kJ/m^2 at 180℃, respectively. Dynamic strain aging （DSA） was also observed to occur when the temperature exceeded 260℃ with a certain strain rate. Both the dislocation density and the number of small dislocation cells effectively increased because of the occurrence of DSA; as a consequence, crack propagation was more strongly inhibited in the steel. Simultaneously, an increasing number of fine carbides precipitated under high stress at temperatures greater than 260℃. Thus, the deformation resistance of the steel was improved and the Jo was enhanced.

关 键 词：low alloyed steel fracture toughness fracture behavior TEMPERATURE dynamic strain aging nuclear power plants 

分 类 号：TG142.1[一般工业技术—材料科学与工程]