铝制封闭母线焊接接头的超声波检测方法及缺陷定位

Ultrasonic Testing and Defect Positioning for Welded Joints of Aluminum Enclosed Busbar

封闭母线的材质主要为铝或铝合金,其声速与钢材有很大差别。现行标准规定,在检测此类焊缝时,需要特别制作铝制试块,增加了检测成本。讨论了在不制作铝试块的前提下的铝制封闭母线的超声波检测方法。介绍了探头K值的换算公式以及取值范围,DAC曲线的制作方法。通过检测实例表明,该检测方法定位准确,定位误差<2%。但是在检测时,对直径<159mm的母线,应制作铝制对比试块。

The material of closed busbar is mainly aluminum or aluminum alloy, and its sound speed is greatly different to steel. The current standards provided that the detection of such welds required a special aluminum block, thus increasing the cost of testing. The testing method without aluminum block was discussed. The calculating formula and value range of K, and the drawing method of DAC curves were introduced. Detecting examples showed that the testing method was accurate in position with positioning error being less than 2%. In addition, to evaluate the defects on the busbar of diameter 〈159mm, an aluminum reference block should be used to produce the DAC curve.