刮板输送机圆环链的金属磁记忆检测及损伤评价

摘要

圆环链断链是引起刮板输送机故障的重要因素,将金属磁记忆检测技术应用于圆环链的检测和损伤评价有其特殊的意义.通过测量磁信号,能够发现应力集中的部位,跟踪变化趋势,实现对圆环链损伤程度的有效评价,从而防止断裂事故发生.对某选煤厂刮板输送机的新链和使用时间不同的三种圆环链进行磁记忆检测,获得不同磨损状态圆环链的残余磁场强度.结果表明:圆环链的使用时间越长,残余磁场强度均值越大,残余磁场强度差数模量和标准差也明显增加,其损伤程度也越严重.该研究应用多个参数对磁记忆检测结果进行分析,综合评价圆环链的损伤程度,为圆环链的无损检测和损伤评价提供新方法和新途径.%The ring chain breakage constitutes an important factor behind the failure of the scraper conveyors,which explains why it is so important to apply metal magnetic memory testing technique to the detection and damage evaluation of ring chain.Magnetic signal measurement affords the ability to find the stress concentration areas,follow the variation tendency,achieve the effective evaluation of the damage degree of the ring chain,and thereby prevent the occurrence of fracture.This paper describes the magnetic memory test of both a new chain of scraper conveyor in a coal preparation plant and three ring chains with different using time and provides the residual magnetic field intensity of ring chains with different wear states.The deeper analysis of testing magnetic signals verifies that a longer use of ring chain is associated with a larger mean value of residual magnetic intensity,suggesting a significant increase in the absolute value and the standard deviation of residual magnetic field intensity differences and the resultant more serious injury.The research drawing on the analysis of the results of magnetic memory test using multiple parameters and the comprehensive evaluation of the damage degree of ring chain may provide a new method for nondestructive test and damage evaluation of ring chains.