Surface Integrity and Fracture Resistance of Engineering Metallic Materials and Components

The mechanical properties of engineering metallic materials are depended on the microstructure.The fracture resistance properties induced by the surface cracking on the metallic components,such as fatigue fracture,stress corrosion cracking as well as haydrogen embrittlement fracture,are depended firstly on its surface integrity.The restricted definition of the surface integrity is given and the surface integrity parameters related directly with macroembrittlement fracture resistance properties,such as the surface microstructure parameter,mechanical property parameter in the surface layer,residual stress parameter in the surface layer as well as the surface stress concentration parameter,are discussed.It has been pointed out that the macro-embirttlement fracture resistance can be increased by means of the surface strengthening technology through the change in the surface integrity of the component.