Gas carburizing method

...A type of surface hardening method in which carbon penetrates and dissolves into the surface layer of low-carbon steel or low-alloy steel (a type of steel with few alloying elements and added amounts) that has a relatively low carbon content and is tough. When quenched after carburizing, the surface becomes harder and has good wear resistance, while the core becomes a material that is tough and highly impact resistant, so it is used for gears, piston rings, and the sliding parts of machine parts. Depending on the type of carbon source, carburizing can be divided into solid carburizing, liquid carburizing, and gas carburizing. Steel made by carburizing is called case-hardened steel. ...

*Some of the terminology used in reference to the "gas carburizing method" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…比較的炭素量の少ない靱性（じんせい）のある低炭素鋼，低合金鋼(合金元素の種類，添加量の少ない鋼)の表面層に炭素を浸入固溶させる表面硬化法の一種。浸炭後に焼入れすると，表面はより硬く，耐摩耗性が良好で，芯部は強靱で衝撃抵抗の高い材料となるので，歯車，ピストンリング，機械部品の摺動部などに加工される。浸炭は，その炭素源の種類により，固体浸炭法，液体浸炭法，気体(ガス)浸炭法に分けられる。なお，浸炭によって造られた鋼を肌焼鋼という。…

※「ガス浸炭法」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報