某电厂后屏过热器管泄漏原因分析

范章帅

doi:10.16577/j.cnki.42-1215/tb.2021.02.028

材料保护 >

2021 , Vol. 54 >Issue 2: 152 - 156

DOI: https://doi.org/10.16577/j.cnki.42-1215/tb.2021.02.028

实用技术

某电厂后屏过热器管泄漏原因分析

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中国大唐集团科学技术研究院有限公司华中电力试验研究院

范章帅(1992-)，工程师，硕士，主要从事电站金属监督方面的工作，电话：18638110287，E-mail：fanzs_1@163.com

收稿日期: 2019-10-09

网络出版日期: 2025-07-10

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Analysis on Leakage Reason of Rear Platen Superheater Tube in One Power Plant

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(Huazhong Electric Power Test Research Institute, China Datang Group Science and Technology Research Institute Co., Ltd., Zhengzhou 450000, China)

Received date: 2019-10-09

Online published: 2025-07-10

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摘要

对某电厂材质为12Cr1MoV的后屏过热器泄漏管及附近管段进行了宏观检验、显微组织分析、力学性能试验。试验结果表明：爆口处无明显减薄，爆口附近存在多个轴向裂纹；爆口试样显微组织老化级别为5级，裂纹附近及远离裂纹部位存在大量蠕变空洞，裂纹呈沿晶断裂特征，为典型的蠕变裂纹；爆口管抗拉强度远低于标准要求；泄漏管附近管段组织老化4.5级，抗拉强度略低于标准要求；后屏过热器出口壁温测点监测数据表明机组长期处于超温运行状态。根据以上分析得出后屏过热器泄漏原因为机组长期超温运行导致后屏过热器管组织老化、性能劣化，进而在蒸汽内压作用下发生爆管。

关键词： 后屏过热器管; 泄漏; 组织老化; 蠕变裂纹; 长期超温

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范章帅 . 某电厂后屏过热器管泄漏原因分析[J]. 材料保护, 2021 , 54(2) : 152 -156 . DOI: 10.16577/j.cnki.42-1215/tb.2021.02.028

Abstract

Macroscopic examination, microstructural analysis and mechanical properties test were carried out on the leak tube of 12Cr1MoV rear platen superheater and its adjacent sections in a power plant. Results showed that there was no obvious thinning at the blasting mouth and there were many axial cracks near the blasting mouth. The aging grade of the blasting specimen was 5 grade with a lot of creep voids near and far from the crack. The crack was characterized by intergranular fracture and was a typical creep crack. The tensile strength of the burst tube was far below the standard requirement. The microstructure aging of the pipeline near the leakage tube was 4.5 grade, and the tensile strength was slightly below the standard requirement. The monitoring data of wall temperature measurement points at the outlet of rear platen superheater showed that the unit had been in over-temperature operation for a long time. According to the above analysis, it could be concluded that the leakage of rear platen superheater was caused by the aging of the structure and deterioration of the performance of the rear panel superheater tube caused by the long-term over-temperature operation of the unit, and then the tube burst under the action of internal steam pressure.

Key words： rear platen superheater tube; leakage; microstructure aging; creep crack; long-time over temperature

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