Residual stresses in ground steels

A new X-ray method for the evaluation of three dimensional (residual) stress states is demonstrated by studies of the effect of grinding on Armco iron and a medium carbon steel. Although the penetration depth of the Cr-radiation employed in this study is only 5 μm, there is evidence of residual stresses normal to the surface (normal and shear components). In the past it has been assumed that these stress components can be neglected. Shear stresses normal to the surface are small in Armco iron, but significant (± 60 MPa) in steel. From the sign of the shears, the direction of final grinding can be determined. Cooling decreases the tensile stresses parallel to the surface in steel; surprisingly, the opposite result is found in Armco iron.