Stress Mapping on Ultrahigh Strength Steel Cut Edges

Metal shearing operations are a stage in the process route from steel plate to finished product which may introduce stress that can be detrimental at later stages of the products life. This is especially true in connection with hydrogen embrittlement-induced fracture. One prerequisite for hydrogen embrittlement is concentrations of residual stresses. During cutting operations, residual stresses originating from plastic deformation are introduced. Herein, how pencil-beam high-energy X-ray diffraction using synchrotron radiation can be used to map stresses down to the microscale is demonstrated. The effects of alternative cutting methods, namely, milling after shearing and laser cutting, that are believed to relieve or to lessen the stress effect on the materials, are also presented. The residual stress measurements using diffraction data are supported using high-resolution hardness measurements