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X射线测量应力一般是用特性X射线穿透深度相应的一种加权平均值来评定材料表面的应力.对由压延和磨削加工等产生表层应力梯度的材料,要测量其残余应力分布,用经典的sin~2(?)法评定是困难的.因此,为评定这类应力分布,已提出多种新的测量方法.本研究是根据两种特性X射线对金属的不同穿透深度,无损测量表层残余应力深度方向分布的简易方法.此法可用于测量木材加工用的带形锯钢材(JIS SKS51)在压延加工、热处理及磨削加工后所产生的残余应力.为研究简易法的实用性,也用逐层削薄法精测了深度方向上的残余应力分布的变化.此时,对逐层削薄法测得的量值,根据X射线的穿透深度作了修正.这里对这种方法也同时作一介绍.在理论分析中,假定平板试样呈各向同性,且残余应力只考虑与板厚z方向有关的平面应力状态.2 理论2.1 逐层削薄法与测量衍射角的X射线透过深度的修正方法
X-ray measurement of stress is generally based on the characteristic X-ray penetration depth corresponding to a weighted average to assess the material surface stress.For calendering and grinding to produce surface stress gradient material, to measure the residual stress distribution, with The classical sin ~ 2 (?) Method is difficult to assess.Therefore, a variety of new measurement methods have been proposed to assess the stress distribution.This study is based on the different penetration depth of X-ray to metal, This method can be used to measure the residual stress generated by the rolling, heat treatment and grinding of the band saw steel for wood processing (JIS SKS51). In order to study the practicality of the simple method The thin layer method was also used to finely measure the variation of the residual stress distribution in the depth direction. At this time, the value measured by layer thinning was corrected according to the penetration depth of X-ray. In the theoretical analysis, it is assumed that the flat specimen is isotropic, and the residual stress only considers the plane stress state related to the z-direction of the sheet thickness.2 Theory 2.1 The layer thinning method and the measurement of diffraction X-ray angle Over the depth of the correction method