【作者】 周家蕤； 强文江； 任爱； 赵彦芬；

【Author】 Zhou Jiarui~1 Qiang Wenjiang~1 Ren Ai~2 Zhao Yanfen~2 (1 School of Materials Science and Engineering USTB Beijing 100083; 2 Suzhou Nuclear Power Research Institute Shuzhou 215004)

【机构】 北京科技大学材料科学与工程学院； 苏州热工研究院；

【摘要】 磁性无损检测方法可以有效地检测电厂过热器奥氏体不锈钢管道的内氧化皮剥落堆积情况。本文对单磁极磁化方式的磁性无损检测仪的特性进行了测试研究得出该仪器的检测信号强度与管内氧化皮厚度之间的量化关系。测试结果表明:检测信号的强度随着氧化皮堆积厚度的增加而呈指数规律增大并趋于其饱和值。检测信号的饱和值随着检测管壁厚度的增加呈指数规律减小,而增大探头中永磁体的尺寸,合理选择其形状,可以弥补检测信号随着管壁厚度增大而衰减带来的不利影响。更多还原

【Abstract】 Magnetic non-destructive test method is proved to be an effective method to detect the oxide scale piled up inside the austenitic stainless steel super-heater tubes of power plant boiler In this paper the characteristics of a magnetic NDT apparatus has been investigated whose detector has a rectangular permanent magnet with only one magnetic pole in contact with the inspected tube According to a large number of tests the quantitative relationship between the output signal of the apparatus and the thickness of oxide scale in stainless steel tubes has been determined The experimental results indicated that the output signals increase in a asymptotic exponential growth manner as the thickness of the oxide scale increases The output signal including the saturation one decreases exponentially with increased thickness of the tube.Using larger magnet and choosing proper shape of the magnet in the detector can effectively enhance the output signal so as to obtain a compensation to the increase of the tube thickness from the viewpoint of the output signal intensity.更多还原