| 摘要 |
PURPOSE:Titled pin for chain having a superior shock resistance and abrasion resistance, obtained by performing chromizing treatment of the pin blank steel composed of specific component composition. CONSTITUTION:Chromizing treatment of pin blank composed of 0.4-0.7% carbon, the rest Mn, Si and residual % Fe and impurities, is performed and chromium layer is formed on the surface of blank and then, chromium carbides are dotted in the chromium layer. For example, the pin blank having said composition, is buried in the powder containing 98% metallic Cr, 2% NH4Cl and is allowed to cool after maintaining at about 1,000 deg.C for about 3hr. Oil hardening is performed moreover after maintaining at about 880 deg.C for about 45min. Chromium layer composed of homogeneous solid solution of Cr and Fe, is formed on the surface of said material and moreover, many chromium carbides combined with C in the steel in the chromium layer, are dotted. Hereby, the pin for chain having superior resistances to shock, abrasion and heat, can be obtained. |
