Oil-immersion quenching cooling precursor and oil-immersion quenching cooling method

An oil-immersion quenching cooling precursor of a workpiece that is of an axle type or has sections in an axle form, comprising:

• a plurality of separation rings on the axle-type workpiece or workpiece that has sections in an axle formed in an axial direction of the workpiece, the plurality of separation rings separating the workpiece into a plurality of sections, each of the plurality of sections having a same constant diameter between a pair of the separation rings, and each of the plurality of separation rings having same dimensions;
• wherein
• a length (L) or base thickness of a part of a separation ring that is coupled with an outer surface of the workpiece in the axial direction of the workpiece is 1-20 mm,
• a height (h) of an outer edge of a separation ring of the plurality of separation rings in relation to the outer surface of the workpiece in a radial direction of the workpiece is 1-10 mm,
• a spacing (b) between adjacent separation rings is 10 mm-200 mm, and
• at least one separation ring of the plurality of separation rings has an upper surface that is perpendicular to an axis of the workpiece and a lower surface opposite the upper surface, the lower surface being sloped relative to the axis.