单层均质电渣堆焊在VVER型核电机组稳压器上的应用

Application of Single-layer Homogeneous Electroslag Cladding on the Pressurizer of VVER Nuclear Power Unit

传统的核电机组主设备内表面防腐蚀堆焊采用双层埋弧自动焊工艺,焊材用量大,耗时高,堆焊层缺陷较多,单层均质电渣堆焊工艺的技术及经济指标更为优异,但因焊材质量问题一直未能得到实际应用。通过实验选用了OK Band 11.72焊带与OK Flux 10.10焊剂的焊材组合,采用电渣堆焊工艺熔敷单层均质防腐蚀层,其熔敷金属在综合机械性能、抗晶间腐蚀能力、稳定的抗热裂纹形成能力、避免再热裂纹等方面满足标准要求,并具有非金属夹杂含量低,焊接缺陷少等特点。经论证可以用于VVER型核电机组稳压器内表面防腐蚀层的堆焊,并总结了实际堆焊时应注意的问题与改进措施。

The anti-corrosion cladding of the main equipment of nuclear power plant traditionally adopts doublelayer submerged arc automatic welding,with high operation time and the amount of welding material consumption,as well as more defects in deposited metal.The single-layer homogeneous electric slag cladding process has better technical and economic indicators than traditional process,but has not been practically applied because of the welding material quality problem.Through the experiment,the welding material combination of OK Band 11.72and OK Flux 10.10was selected,using electric slag cladding process to melt single layer homogeneous anticorrosion layer,the deposited metal meets the standard requirements in comprehensive mechanical properties,corrosion resistance,stable resistance heat crack formation ability,avoid reheat crack,and has the characteristics of low non-metal inclusion content,less welding defects,etc.It is demonstrated that it can be used for surfacing welding of the inner-surface anti-corrosion layer of the pressurizer of the VVER nuclear power plant,and the problems and improvement measures that should be paid attention to in the actual surfacing welding are summarized.