超大规格300M钢棒超声波探伤及缺陷分析

Ultrasonic Detection and Defects Analysis of Large Size 300M Steel Bars

对Φ450 mm规格的300M钢棒材进行了超声波探伤,采用2.5 MHz软膜探头可以保证探伤的灵敏度并降低噪声水平。通过宏观、显微观察和能谱分析等手段对探伤缺陷进行了分析。结果表明:探伤缺陷处存在氧化铝、氧化镁和氧化钙复合夹杂物,单个夹杂物最大尺寸可达100μm。该缺陷属于熔炼过程中引入的外来夹杂物,对材料性能有不利的影响。

The 300M steel bars with diameter of 450 mm were inspected by ultrasonic method. 2.5MHz soft probe was used to ensure ultrasonic sensitivity and reduce the noise level. Macro- and micro-observations as ,well as electrical diffraction spectrum analysis were carried out to inspect interior defects of a material. The results showed that inclusions found by ultrasonic detection were consisted of Al1O3 ,MgO and CaO. The largest size of the inclusions was over 100 μm. These inclusions were imported by melting process, and they were detrimental to properties of the material.