这个是我们为国外公司渗氮的要求:Case Depth - is the maximum depth below the surface at which a minimum hardness
equivalent to 50 HRC or 542 HK (Knoop Hardness) is achieved. The hardened case
depth includes the top epsilon layer and the compound (diffusion) layer.
有效硬化层深度 - 是指表面以下至最低硬度为HRC 50或HK542(努氏硬度)处的最大深度。硬化层包
括Epsilon相表层和化合(扩散)层。