Abstract
A new method was proposed to estimate the distribution of residual stress in a sample surface. When a sample surface has stress gradient, we cannot easily understand the stress distribution due to non-linearity of Sin2 ψ diagram. This non-linearity is because probing depth varies with ψ angle. We discussed a new method to estimate Sin2 ψ diagram with maintaining the X-ray incident angle. By using this method, we can obtain Sin2 ψ diagram without changing the probing depth and measure the stress up to the depth in a sample. We report the results of stress measurement in ground stainless steel sample by using our method. The validity of our method is discussed.