利用VB编写检测程序,设计分别与待测凸轮片凸圆和基圆耦合良好的涡流探头,选择3件经过高频感应淬火处理的不同硬度的球墨铸铁凸轮片进行硬度测试。结果表明: 该涡流检测仪能够精确检测球墨铸铁凸轮片的硬度, 与洛氏硬度计检测结果的对比表明其检测精度可达到±1.5 HRC;金相分析结果表明显微组织的不同是导致该3个凸轮片感应淬火层表面硬度高低不同的根本原因。

By programming the eddy current test based on VB and designing two eddy current probes which couple well respectively with the gibbous circle and base circle of the campieces, the hardness of three high-frequency induction quenched nodular cast iron campieces with different surface hardness were tested. The results show that the test precession of the eddy current tester could be ±1.5 HRC according to the test results of Rockwell hardness tester. The metallographic examination results indicate that the difference of microstructure led to the difference of quenched case surface hardness of the three campieces.