| 摘要 |
A ferrous article comprising an integrally bonded hard chromized external layer containing a chromium nitride complex layer is formed by nitriding and chromizing heat treatments. A high carbon chrome steel is cleaned and dried at 200-250 DEG F; heated at 15-35 DEG F. for 90-100 minutes in an atmosphere of endothermic gas, raw natural gas and ammonia; quenched in oil and air cooled. It is then reheated to 325-350 DEG F; drawn to relieve stresses and chromized. The Cr is diffused into the article from a source, a Cr hydrohalide powder pack or a Cr composition coating applied to the article. |
