NF A95-321-2:1988
粉末冶金.硬质合金除外的烧结金属材料.表面硬度的测定.第2部分:表面富集碳或碳和氮的表面硬化钢铁材料
Powder metallurgy. Sintered metal materials, excluding hardmetals. Determination of apparent hardness. Part 2 : case-hardened ferrous materials, surface enriched by carbon or carbon and nitrogen.