| 摘要 |
PURPOSE:To enhance the extent of deposition efficiency to a cylinder head in a clad seat layer by forming a plastic deformation layer in a base metal surface layer at the underside of the clad seat layer formed in a part equivalent to a valve seat of the cylinder head. CONSTITUTION:A port part 2 is formed in a cylinder head body 1, and this port part 2 is opened to a recess 3 at the side of a combustion chamber. Likewise, a valve seat surface 5, with which a valve 4 comes into contact, is formed in an opening end of the port part 2. In addition, the valve seat surface 5 is partitioned off by a clad seat layer 6 padded by laser cladding. In the above constitution, a plastic deformation layer 7 plastically deformed by a mill roller or the like is formed in a base metal surface layer at the underside (side of the cylinder head 1) of the clad seat layer 6. With this constitution, a defect 8 such as a pinhole or the like so far existing in the cylinder head body 1 (base metal part) is brought to nothing in substance at a part of the plastic deformation layer 7. |
