| 摘要 |
PURPOSE:To provide a coiled spring or so of automobiles, which has less possibilities in occurance of pitting corrosion and prominent characteristics of corrosion fatigue by spreading a coat which contains metal chromic powder having a specific weight percent over the surface as widely as an area having a specific area ratio. CONSTITUTION:In a suspension spring such as a coiled spring of an automobile, a coat containing metal chromic powder 60-97% in weight percent is applied on the surface of the spring as much as 20-1,200g/m<2>. The metal chromic powder is prepared by using an atomized method and an average diameter of the particles is approximately 0.1-10mu. The coat of a paint which is composed of color spreading agent containing hardening agent, sigment, solvent and so on is applied on the surface of the spring by various methods and then dried to harden at a normal temperature or under the heating condition. The resulting coat containing the metal chromic powder restrains growth of a pit due to corrosion and prevents a fatigue crack which grows from a deep pit as an initial point, hence providing a coated spring superior in corrosion fatigue characteristics. |
