锅炉受热面奥氏体不锈钢管弯头表面裂纹涡流检测技术研究

Study on eddy current testing technique of austenitic stainless steel tube elbow surface crack for boiler heating surface in thermal power plants

针对火电厂锅炉受热面奥氏体不锈钢管弯头涡流检测的特点,设计制作马鞍型阵列式涡流探头和对比试样,改进升级ET-556H多频涡流检测仪,并通过试验提出火电厂锅炉受热面奥氏体不锈钢管弯头涡流检测的最佳参数。本涡流检测技术不仅方便操作,而且可提高检测分辨率和灵敏度,对于火电厂锅炉受热面奥氏体不锈钢管外表面0.4 mm深的周向线性缺陷和0.5 mm深的轴向线性缺陷具有较高的检测灵敏度。

For eddy current testing characteristics of austenitic stainless steel tube elbow of the boiler heating surface,saddle array eddy current sensors and reference blocks were designed and made,and ET-556H multi-frequency eddy current analyzer were improved.The best parameters of eddy current testing of austenitic stainless steel tube elbow for boiler heating surface were proposed by experiment.The eddy current testing technique is easy to operate,and can improve the detection resolution and sensitivity.Especially it is with high sensitivity for 0.4mm deep circumferential linear defects and 0.5mm deep axial linear defects of outer surface of austenitic stainless steel.