一、新制车轴的贯通性检验采用超声波探伤方法检测车轴钢材,可发现的缺陷种类很多。由于铁道部对轴坯钢只要求控制内部缩孔、气孔以及检测热处理后的晶粒度,而对其他缺陷(如疏松、带状组织、白点和金属夹杂物)没有严格的要求,因此要求无损检测者来承担这项工作是不合理的。自从应用超声波探伤方法检测车轴轴坯以来,许多工厂(如浦镇、齐齐哈尔、哈尔滨等车辆工厂)在锻轴时,测出轴坯内部存在着许多气孔、长条状的缩孔与分解而超过 First, the continuity of the new axle inspection Ultrasonic testing methods to detect the axle steel can be found in many different types of defects. Since the Ministry of Railways only requires the control of internal shrinkage cavities and pores as well as the grain size after heat treatment, other defects such as looseness, banded structure, white spots and metal inclusions are not strictly required. Therefore, the requirements It is unreasonable for NDT operators to undertake this work. Since the application of ultrasonic testing to detect shaft billet, many factories (such as Puzhen, Qiqihar, Harbin and other vehicle factory) in the forging shaft, measured within the shaft billet there are many stomatal, long cavity shrinkage and decomposition of more than