Residual stresses in borieded layers

Pure iron (Armco-iron) was borided. A 100 micrometer thick surface layer consists of FeB at the immediate surface and Fe sub B in deeper regions, followed by a diffusion layer. X-ray stress analysis proves to be an appropriate method to determine the residual stresses non-destructively. At the surface a residual compressive stress of 600 MPa is found. Its variation with depth below the surface is determined.