case.hard.en
v.tr.（及物动词）case.hard.ened,case.hard.en.ing,case.hard.ens To harden the surface or case of (iron or steel) by high-temperature shallow infusion of carbon followed by quenching.表面渗碳硬化法：通过高温条件下对碳的浅层注入并紧接冷却来使（铁或钢的）表面或外壳硬化To make callous or insensitive.使冷漠或不敏感
