【摘要】 奥氏体不锈钢管道焊缝缺陷的检测已引起无损探伤人员的密切关注.今利用超声相控阵技术对奥氏体不锈钢管道焊缝缺陷进行检测,并与20#碳钢检测成像效果进行比对.结果表明,相控阵超声波在20#碳钢中有很好的穿透性,而在奥氏体不锈钢焊缝中超声波信号衰减较为严重.奥氏体不锈钢焊缝区域缺陷信号信噪比最大值为9dB,当探伤深度大于30mm时,其信号衰减符合衰减方程描述.对于焊缝区域深度大于50mm,尺寸小于2mm的横通孔,超声相控阵技术无法清晰地探伤到此类缺陷.对于奥氏体不锈钢焊缝,横波检测成像的信噪比要高于纵波.更多还原

【Abstract】 The detection of defects in austenitic stainless steel was focused in the NDT field.The ultrasonic phased array was used to detect the defects in austentic stainless steel pipeline welds.The detection results of the two specimen blocks(the 20#carbon steel block and the austentic stainless steel block)were compared in detail.It showed that the ultrasonic wave could penetrate the carbon steel block easily,while the ultrasonic wave energy decreased rapidly in the austenitic steel block.The largest signal noise ratio of ultrasonic wave echo signals in austenic stainless steel blocks was just 9dB.The significant attenuation satisfied the rule of attenuation equation,when the defect depth was more than 30 mm.It was difficult to detect the horizontal hole of the size of2mm when the defect depth was more than 50 mm.Compared with the longitudinal wave detection,a better SNR can be got by transverse wave detection.更多还原