核反应堆用不锈钢老化性能再生研究

Toward Regeneration of Aged Reactor Stainless Steels

针对核反应堆用奥氏体不锈钢和铸造双相不锈钢长期服役会发生严重的热老化脆化问题,导致材料发生脆性断裂的概率增大,严重威胁核反应堆的安全运行。在系统研究时效老化对不锈钢力学性能和微观组织演变影响的基础上,提出利用"第二相粒子与基体电学性能差异"这一特性,对长期服役老化的不锈钢进行性能修复。研究结果表明:经电磁外场处理后,长期老化不锈钢基体中的有害析出相数密度和调幅分解程度显著下降,不锈钢的韧性得到有效修复,材料的老化程度明显降低,使得不锈钢材料的服役寿命延长近一倍。

After long-term operation,the austenitic stainless steel and cast duplex stainless steel used in nuclear power plants are subjected to serious thermal aging embrittlement,including hardness increasing,toughness decreasing and the raising of the probability of brittle fracture,which severely threatens the safe operation of the nuclear power plant.Based on the systematic study of the effect of thermal aging on the mechanical properties and microstructural evolution of stainless steels,the characteristics of the electrical property difference between the particle and matrix is utilized to repair the degraded performance of aged stainless steels,that is a novel processing technology.The study shows that after the electromagnetic field processing,the number density of precipitates and spinodal decomposition in aged stainless steel is significant reduced,and the degraded toughness is effectively repaired.Therefore,the service life of aged stainless steel has almost been doubled.