有一种空心的零件是用38Cr钢管制成,淬火后要求内外表面硬度均在HRC32～38范围内,淬火时用硝盐等温冷却,在放入冷却剂时,如果将零件的底先下去,不但因浮力大压不下去,而且容易造成零件内表面冷却不足,如果将零件斜放下去,容易引起淬火变形,如果将零件口部向下放入冷却剂中,则因零件空腔内的空气排不出去而产生浮力,零件压不下去,即使压下 There is a hollow part is made of 38Cr steel, after quenching both inside and outside surface hardness are required in the range of HRC32 ~ 38, quenching with salt isothermal cooling, when placed in the coolant, if the parts of the bottom go down, not only Due to the buoyant pressure can not go down, and easily lead to insufficient cooling of the inner surface of the part, if the parts are inclined down, easily lead to quench deformation, if the part mouth down into the coolant, Do not go out and produce buoyancy, parts pressure does not go down, even if pressed