Privacy | Log in | Web agency: Ars Media. ; Advertising Center // --> { When high-carbon steels are case-hardened, the hardness penetrates the core and causes the metal to become brittle. - Carburizing is a case-hardening process by which carbon is added to the surface of low-carbon steel. Engineering Book Store DFM DFA Training It differs from the other methods in that the individual parts have been heat-treated and tempered before nitriding. Two methods are used for carburizing steel. Carbon steels are not very hardenable ; therefore wide pieces cannot be through-hardened. Applications & Design. document.write('');