全因子试验设计在X射线衍射法测试高应力标样残余应力值中的应用

Application of Full Factorial Experiment Design in Residual Stress Measurement of High Stress Standard Sample by X-ray Diffraction Method

针对X射线法测试残余应力值的主要参数——准直器直径、曝光时间和β角数量,依据6σ的DMAIC流程和全因子试验设计,研究了标准高应力试样残余应力值的测试方法。结果表明:上述参数对探测器X光子接收数量、衍射峰强度和峰背比的大小有较大影响。为提高测试精确度和重复性,在满足检测效率的前提下,可选择较小的准直器直径、较长的曝光时间和较大的β角数量进行残余应力测试。对于标准高应力试样,选择2mm准直管、3s曝光时间和11个β角参数测定的残余应力值与标准值最为接近。

A DMAIC flow of 6σ was made to study the influence of the parameters such as aperture diameter, exposure time and number of β angle on residual stress measurement of high stress standard sample by X-ray diffraction method. The results of full factorial experiment showed that the parameters had an great effect on amount of X photon, intensity of X-ray diffraction peak and ration of diffraction peak to background. On the premise of meeting the conditions of detecting efficiency, small aperture diameter, long exposure time and large number of β angle could increase accuracy and decrease repeatability error of the test results. According to the high stress standard sample, choose 2 mm aperture diameter, 3 s exposure time and 11β angle could meet the requirements of the related standard value.