无缝钢管的分层缺陷是由于制造无缝钢管的圆钢坯内的非金属夹杂物在穿孔轧管过程中被进一步拉长所产生的。分层缺陷的存在降低了无缝钢管承受载荷的能力，易造成应力集中，影响钢管的安全使用。对无缝钢管的分层缺陷采用相控阵超声检测技术进行检测，结果表明，相控阵超声检测技术对于分层缺陷有很高的检出率，同时能够形象地展现缺陷的形貌特征，是分层缺陷检测的有效手段。

The layered defects of seamless steel tube are caused by the further elongation of the non-metallic inclusions in the circular steel billet during rolling of the seamless steel pipe. The existence of the layered defect reduces the ability of seamless steel tube to bear the load, which causes stress concentration and affects the safe use of steel pipe. Phased array ultrasonic testing technology due to its own technical characteristics, has a high detection rate for layered defects, at the same time can image display defect appearance characteristics, and it is an effective method for layered defect detection.