摘要
The Charpy impact properties of 15Cr12MoVWN ferritic/martensitic steel for sodium-cooled reactors with variation in heat treatment factors and parameters are reported.The results show that the ductile-to-brittle transition temperature(DBTT)increased and the upper shelf energy(USE)decreased with increase in normalizing temperature.However,the variation tendency of DBTT and USE was the opposite with increase in tempering temperature.The tempering temperature showed a greater influence on USE than the normalizing temperature,and normalizing and tempering temperatures had the equally significant effects on DBTT,but the cooling method was not a significant factor for DBTT and USE.The prior austenite grain and M_(23)C_(6) size were the main influences on DBTT,and the dislocation density was the main factor affecting the variation of USE.The heat-treatment regime recommended for 15Cr12MoVWN steel was composed of normalizing at 1000-1050℃ for 0.5 h followed by water quenching or air cooling and tempering at 760℃ for 1.5 h.
基金
supported by the Natural Science Foundation Guidance Plan of Liaoning Province(No.2019-ZD-0362).
