非金属夹杂物对TP316L无缝钢管超声波探伤的影响

Effect by Nonmetallic Inclusions on Ultrasonic Detection of TP316L Seamless Steel Tube

φ32mm×2 mm规格TP316L无缝钢管在超声波探伤时出现大批内层伤报警.探伤合格率仅为60%。为研究探伤报警的原因,首先对钢管进行着色探伤,未发现内外表面存在裂纹缺陷;定位缺陷位置后截取金相试样,分析发现造成探伤不合格的原因是钢管内部存在片状非金属夹杂物,该非金属夹杂物主要由硅酸盐类和氧化铝类夹杂物组成。

A great number of inner layer flaw alarms are triggered with the φ32mm×2 mm TP316L seamless steel pipes as being ultrasonic detected,and the conformance rate is just 60%.In order to identify the causes for the said alarms,firstly the pipe is subjected to dye detection,and no crack is found on both outer and inner surfaces thereof;and then the metallographic test sample is taken after the defect is located.As a result of the analysis it is concluded that the above mentioned nonconformance is attributed to the lamellar nonmetallic inclusions inside the steel pipe which are mainly the silicate and alumina inclusions.