弱铁磁性奥氏体不锈钢管内氧化皮检测技术  

Detection technique of oxide scales blockage in austenitic stainless steel tubes with weak ferromagnetism

作　　者：刘峰[1] 张帅 张双楠[2] 蔡桂喜[2] 李建奎[2] LIU Feng;ZHANG Shuai;ZHANG Shuangnan;CAI Guixi;LI Jiankui(School of Mechanical Engineering,Liaoning Petrochemical University,Fushun 113001,Liaoning,China;Materials Servicing Behavior Research Department,Institute of Metal Research of Chinese Academy of Sciences,Shenyang 110016,Liaoning,China)

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001 [2]中国科学院金属研究所材料使役行为研究部,辽宁沈阳110016

出　　处：《沈阳工业大学学报》2025年第1期73-82,共10页Journal of Shenyang University of Technology

基　　金：辽宁省教育厅基金项目(L2020007)。

摘　　要：【目的】为提高机组发电效率和加快发展绿色低碳经济,超(超)临界机组已经逐渐成为国内火力发电的主力机组。作为超(超)临界机组的关键部件,锅炉管大多采用奥氏体不锈钢管制作。锅炉管长期在高温高压和蒸汽的环境下服役,管道内壁因发生氧化而产生氧化皮。机组的启停导致内壁的氧化皮易发生脱落并堆积在管内,当氧化皮的堆积量达到一定程度时会导致管道局部堵塞,从而引发爆管事故。然而,现场氧化皮的定量检测一般采用磁性无损检测方法,但冷加工和长期老化等原因使得锅炉管具有弱铁磁性,导致现有的氧化皮磁性定量检测方法的测量结果不准确。【方法】针对弱铁磁性奥氏体不锈钢管内氧化皮堵塞量检测的问题,通过扩大磁路的方式提出了一种新型磁性检测方法。采用有限元模拟将现有磁性检测方法与新型磁性检测方法的仿真结果作对比,分析了现有磁性检测方法无法应用于弱铁磁性锅炉管内氧化皮检测的原因。【结果】对于现有磁性检测方法,当锅炉管有弱铁磁性时,氧化皮堵塞面积比的绝对误差值范围为138%~474%;对于新型磁性检测方法,当锅炉管有弱铁磁性时,氧化皮堵塞面积比的绝对误差值范围为3.4%~6.7%,新型磁性检测方法绝对误差值远小于现有磁性检测方法,新型磁性检测方法受管磁性影响较小,可适用于弱铁磁性锅炉管内氧化皮的定量检测。利用新型磁性检测方法,通过不同壁厚标准试样内不同堵塞面积比氧化皮的检测实验,建立了检测信号值与不同壁厚标准试样内的不同氧化皮堵塞面积比之间的对应关系,验证了上述仿真结果的正确性;通过对装有不同堵塞面积比氧化皮的现场管进行实验,验证了标定公式的正确性,并计算了新型磁性检测方法的检测误差值。试样标定实验测得弱铁磁性试样内氧化皮堵塞面积比的最大绝对误差�[Objective]To improve power generation efficiency and accelerate the development of green and low-carbon economy,supercritical or ultra-supercritical units have gradually become the main units for thermal power generation in China.As a key component of supercritical or ultra-supercritical units,boiler tubes are mostly made of austenitic stainless steel.After being used in an environment of high temperature,high pressure,and steam for a long time,a boiler tube will face an oxidized inner wall,on which oxide scales are produced.Due to the start and stop of the unit and other factors,the oxide scales are easy to fall off and accumulate in the tube.When the accumulation reaches a certain degree,local blockage of the tube occurs,resulting in tube burst.The on-site quantitative detection of oxide scales is generally carried out by magnetic nondestructive detection.However,boiler tubes exhibit weak ferromagnetism due to cold working and long-term aging,which makes the results of existing magnetic quantitative detection method for oxide scales inaccurate.[Methods]To realize the accurate detection of oxide scale blockage in austenitic stainless steel tubes with weak ferromagnetism,this paper proposed a new magnetic detection method based on the enlargement of the magnetic circuit.The present study compared the simulation results of the existing magnetic detection method and the new one by finite element simulation and probed into the reasons why the existing method failed to accurately detect oxide scales in boiler tubes with weak ferromagnetism.[Results]The simulation results show that the absolute error of the proportion of the oxide scales blockage area is 138%-474%in boiler tubes with weak ferromagnetism when the existing magnetic detection method is employed,while that is 3.4%-6.7%in the case of using the new magnetic detection method.In short,the new magnetic detection method has a much smaller absolute error than the existing one,able to be applied to the quantitative detection of oxide scales in boiler tubes with

关 键 词：弱铁磁性 奥氏体不锈钢管 氧化皮 仿真 磁路 磁性检测 有限元 无损检测 

分 类 号：TH878[机械工程—仪器科学与技术] TG115[机械工程—精密仪器及机械]