我们有国外零件是氮碳共渗,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. 界限硬度值是50HRC,不是用洛氏硬度测量,我们是513HV,因为我们不能测HK。