电焊机2025，Vol.55Issue(7)：112-117,6.DOI:10.7512/j.issn.1001-2303.2025.07.12
某核电厂12Cr2Mo1R钢高温蒸汽管道龟裂原因分析
Chaping Analysis of High Temperature Steam Pipe of 12Cr2Mo1R Steel for A Million-kilowatt Nuclear Power Plant
曾勇 1梁元梦 1银帮耀 1邓江勇 1王琪1
作者信息
- 1. 广西防城港核电有限公司,广西 防城港 538000
- 折叠
摘要
Abstract
To investigate the chapped-like crack formation on the outer surface of a 12Cr2Mo1R steel high-temperature steam pipe in a nuclear power unit,systematic analysis was conducted using non-destructive testing,chemical composition analysis,metallographic observation,energy spectrum analysis,fracture characterization,and microhardness testing.Results indicated that the carbon content in the cracked region(0.057 wt.%)was significantly lower than the standard requirement(0.08-0.15 wt.%)and adjacent non-cracked areas(0.11 wt.%).The microstructure of the cracked zone exhibited ferrite+trace granular bainite,markedly differing from the normal region's structure,confirming localized oxidative decarburiza-tion.The depth of the decarburized layer(～1 625 μm)aligned with the crack propagation depth,and the decarburized area showed grain coarsening and a substantial hardness reduction,leading to material strength degradation.Further analysis re-vealed that the decarburization originated from abnormal overheating caused by local short-circuit damage of ceramic heat-ing sheets during the preheating stage.During operation,the synergistic effects of organizational stress,thermal stress,and vibration stress induced stress concentration in the decarburized zone,ultimately triggering multi-source crack initiation and propagation at weak strength regions,forming the chapped-like crack morphology.Fracture analysis demonstrated inter-granular/transgranular mixed fracture characteristics in the crack propagation zone,with oxide particles detected within the cracks.This study provides reference insights for failure analysis of cracks in 12Cr2Mo1R steel high-temperature steam pipes of nuclear power units.关键词
12Cr2Mo1R钢/氧化脱碳/龟裂/预热/失效分析Key words
12Cr2Mo1R steel/oxidative decarburization/chapped-like crack/preheating process/failure analysis分类
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曾勇,梁元梦,银帮耀,邓江勇,王琪..某核电厂12Cr2Mo1R钢高温蒸汽管道龟裂原因分析[J].电焊机,2025,55(7):112-117,6.
