ABSTRACT
A method of surface hardening of steel in which parts are packed in a steel box with a carburizing compound and heated to elevated temperatures. Common carburizing compounds contain 8%–10% alkali or alkaline earth metal carbonates (e.g., barium carbonate, BaCO3) bound to hardwood charcoal or to coke by oil, tar, or molasses. This process has been largely supplanted by gas and liquid carburizing processes. See case hardening.
