摘要 |
A selectively case hardened steel article by low temperature carburization includes a body made of a chromium bearing nickel or ferrous based alloy, for example stainless steel, a first portion of the body having a first hardness characteristic, and a second portion of the body having a second hardness characteristic; the second portion being less than the entire body and substantially free of carbides. One method for selective case hardening by low temperature carburization includes the steps of applying a carbon blocking mask over surface areas of the article that are not going to be carburized; activating those surface areas that are to be carburized; diffusing carbon into the activated surface areas at a temperature below which carbides form; and removing the carbon blocking mask. |