C45Cr钢轧材UT不合成因分析与措施

The Cause Analysis and Measures of Ultrasonic Test Defects in the C45Cr Rolling Material

对C45Cr钢轧材UT不合产生原因进行了研究。通过探伤、低倍、高倍及扫描电镜观察等理化检验,对比分析了同一炉号,合格试样与不合格试样的差异。得出结论:钢材中心存在较为严重的碳偏析,高倍观察存在显微孔隙,显微孔隙区域碳偏析严重,显微孔隙加之碳偏析可产生异常组织反射波,导致钢材UT不合格,并依据探伤不合的原因提出改进措施。

The causes of UT disqualification of C45Cr steel rolled products were studied.Through physical and chemical tests such as flaw detection,macrostructure,high magnification and scanning electron microscope observation,the differences between qualified and unqualified samples with the same heat number were compared and analyzed.It is concluded that there is serious carbon segregation in the center of steel and micro pores exist in high-power observation.The carbon segregation is serious in the micro pore area.The abnormal structure reflection wave can be produced by micro pore and carbon segregation,which leads to the disqualification of ultrasonic flaw detection of steel.The improvement measures are proposed according to the causes of unqualified flaw detection.