Case Depth? 表面深度? a process used to case harden steel with a carbon content between 0.1 and 0.3 wt% c. in this process steel is introduced to a carbon rich environment and elevated temperatures for a certain amount of time, and then quenched so that the carbon is locked in the structure 维基上查得的资料 意思很清晰了 注意carbon is locked in the structure这种说法查看更多