| 摘要 |
PURPOSE:To vanish fine vacancies present on the surface of cast steel and to improve the corrosion resistance by subjecting only the surface layer of the cast steel to impactful compressive plastic deformation and by heating the cast steel to the diffusion temp. or above. CONSTITUTION:The surface of cast steel is peened to cause plastic deformation to an extent exceeding the size of fine vacancies present on the surface. The cast steel is then heat treated at >=1,000 deg.C diffusion temp. for >=1hr. By this surface working method, fine vacancies present on the surface of the cast steel and just under the surface are vanished, and the corrosion resistance is improved. |
