摘要
稳压器喷淋阀是核电厂用于反应堆冷却剂系统压力控制和维持一回路均匀水化学的关键设备。针对某核电厂稳压器喷淋阀的碟簧断裂案例,通过宏观形貌分析、尺寸测量、残余应力测试、化学成分分析、硬度测试、显微组织对比分析、第二相分析和断口微观形貌分析,发现碟簧断裂主要原因是热处理工艺不当,晶界处析出大量δ相导致材料韧性降低,并在外载荷作用下发生了沿晶脆性开裂。进而明确了碟簧的固溶热处理要求,即:在最低温度为925~1 010℃之间进行固溶热处理并通过空冷或更快速方式冷却,随后进行结构硬化处理,包括在(720±10)℃保持8 h,然后在炉内降温到(620±10)℃,并在这个温度保持10 h,随后空气冷却。
The pressurizer spray control valve is the key equipment used for pressure control of the reactor coolant system and maintaining uniform water chemistry in the primary circuit in nuclear power plant. In view of the fracture case of the disc spring of the pressurizer spray control valve in a nuclear power plant, through the methods of macro morphology analysis,size measurement, residual stress test, chemical composition analysis, hardness test, microstructure comparative analysis, and second phase analysis and fracture micro morphology analysis, it is concluded that the reason for the fracture of the disc spring is the improper heat treatment process and a large number of cracks at the grain boundary of Phase δ, resulting in the decrease of toughness and intergranular brittle cracking under external load. Then, the requirements for the solution heat treatment of the disc spring are clarified, that is, the solution heat treatment is carried out at the minimum temperature of 925~1010℃ and cooled by air cooling or faster method, and then the structural hardening treatment is carried out, including maintaining at 720±10 ℃ for 8 hours, then cooling in the furnace to 620±10 ℃ and maintaining at this temperature for 10 hours, and then air cooling.
作者
胡文盛
张潇宇
王仪美
吴起
郭超凡
谢祖妙
HU Wensheng;ZHANG Xiaoyu;WANG Yimei;WU Qi;GUO Chaofan;XIE Zumiao(Fujian Fuqing Nuclear Power CO.LTD.,Fuqing of Fujian Prov.350318,China;China Nuclear Power Operation Technology CO.LTD.,Wuhan of Hubei Prov.430073,China;Nuclear Power Operations Research Institute,Shanghai 200126,China)
出处
《核科学与工程》
CAS
CSCD
北大核心
2022年第6期1425-1431,共7页
Nuclear Science and Engineering
关键词
稳压器喷淋阀
碟簧
断裂
机理
热处理
Pressurizer spray control valve
Disc spring
Crack
Mechanism
Heat treatment
