以高切削速度切削钢时,在硬质合金刀具的前面上因形成月牙洼而发生的刀具磨损,曾被认为是由以刀具与工件材料间相互扩散为主的磨损过程所造成。在这种磨损过程的模型之一中就提出,刀具与工件材料间的反应引起刀具组织变化,使其软化,并使刀具材料的碎片被流动中的切屑从刀具表面上机械地切除,还有一种假说,假定由于原子从刀具材料扩散到切屑中去而形成月牙洼. When cutting steel at high cutting speeds, tool wear on the front of cemented carbide tools due to the formation of crescent-shaped depressions was thought to have been caused by a wear-and-tear process that predominated between tool and workpiece material. In one such model of the wear process, it is proposed that the reaction between the tool and the workpiece material causes the tool organization to change, to soften it and to mechanically remove the pieces of tool material from the surface of the tool by the flowing chips, Hypotheses assume that the crescent is formed as the atoms diffuse from the tool material into the chip.