Comparative analysis of residual stress of main components of hydraulic support

Based on the safety problem of comprehensive mechanical mining,taking shield beam and base of hydraulic support as the research objects,the residual stress level is estimated by X-ray method.Tests were carried out on shield beam and base twice before and after heat treatment,and each component was selected multiple areas (more than 40 measuring points) to get the overall level of residual stress and its distribution.The results indicate that welding residual stress in base is higher than that in shield beam before heat treatment,the maximum value is 429.4 MPa(0.62 R_eL),while the maximum value in shield beam is 348 MPa(0.50 R_eL).After heat treatment,the residual stress level decreases significantly,the maximum values of base and shield beam decrease by 37% and 71%,respectively; and the average values decrease by 46% and 76%,respectively.The results show that new heat treatment process has significant effect on reducing residual stress.