Monitoring of rolling wear using the alternating current potential drop method

开发了一套表面损伤评价系统。该系统采用交流电位降（ACPD）法。该系统由一台个人计算机、一个频率发生器、一个功率电流放大器、两个直流放大器和两个高速a /D转换器组成，并采用交流电压感应采集补偿技术。感应拾取是造成ACPD测量误差的最主要原因。采用中碳钢和轴承钢作为滚动磨损试样，进行往复滚动磨损试验。对轧制磨损损伤表面施加交流电流后的ACPD信号进行了测量。利用计算机程序对这些信号进行分析，检测信号之间的相位差。然后对感应拾取进行补偿。本研究得到的结论总结如下：(1)利用补偿技术可以成功地估计出ACPD的真实值。(2)往复滚动磨损过程中产生细小的片状磨损颗粒。(3)从估计ACPD值随周期数的变化可以看出，在约10^5周期前呈下降趋势，约10^5周期后呈上升趋势。其原因可能是由于下部试件磨损引起材料电性能和电流路径的改变。

A surface damage evaluation system was developed. The alternating current potential drop (ACPD) method was used in this system. This system consists of a personal computer, a frequency generator, a power current amplifier, two DC amplifiers and two high speed A/D converters and has a compensating technique for inductive pick-up of AC voltage. The inductive pick-up is the most important cause of measurement error at ACPD method. Middle carbon steel and bearing steel were used for rolling wear specimens, and reciprocating rolling wear tests were carried out. Signals of ACPD from surface which damaged with rolling wear and applied alternating current were measured. These signals were analyzed by computer program and the phase difference between these signals was detected. Then the inductive pick-up was compensated.The conclusions which were obtained in this research are summarized in the following.(1) Using the compensation technique, the true value of ACPD could be estimated successfully.(2) Reciprocating rolling wear proceeds with producing small flaky wear particles.(3) From the change in estimated ACPD values against the number of cycles, it can be seen to the tendency of decreasing before about 10^5 cycles and increasing after about 10^5 cycles. The reason seems to change in the electrical properties of materials and current path caused from wear of lower specimens.