Research on laser reinforcement repair process of cracked 316L stainless steel nuclear power pipes
In order to explore the feasibility of laser reinforcement repair process to repair cracks in stainless steel nuclear power pipelines,a laser deposition repair process experimental study was conducted on the cracks at the welds of 316L pipes with branch pipes.An optical microscope and Vickers hardness tester were used to conduct mi-croscopic structure and hardness analysis on crack repairing,and the effects of different repair process parameters on the micro-structure and micro-hardness were explored.The study shows that within a certain range,when the la-ser power and scanning speed are reduced,an excellent metallurgical bond can be formed between the deposited layer and the substrate;extended grains with obvious directionality are observed in the heat-affected zone,and there are no obvious metallurgical defects such as cracks in the repair area,the microhardness shows an upward trend.Within a reasonable range of process parameters,it was observed that the microstructure of the repair area was mainly composed of equiaxed grains and dendrites.The denser and finer grain structure produced in the repair area increases the average hardness by 8.7%compared with the base metal area,and the highest hardness of the re-paired sample reaches 204HV.
NETL
NSTL
万方数据
