A circulation apparatus recovers cooling fluid after the cooling fluid is used for quenching and supplies the cooling fluid to a defoaming bath. A laminar flow weir of a defoaming apparatus partitions the defoaming bath into laminar and shallow flow baths. The laminar flow weir is lower than a side wall of the laminar flow bath. Cooling fluid from the circulation apparatus is supplied to the laminar flow bath and the cooling fluid is poured into the shallow bath from the laminar flow bath along the laminar flow weir. A filter covers an opening in a bottom portion of the shallow bath. The liquid level height in the shallow bath is less than the height of the laminar flow weir. A supply bath accumulates cooling fluid that passes through the filter, and supplies the cooling fluid to a cooling apparatus that sprays the cooling fluid onto a metallic material.

A bearing ring for a roller bearing includes: an inner layer part that is formed of tempering martensite or sorbite; and a surface layer part that surrounds the entire periphery of the inner layer part, in which Vickers hardness of a surface thereof is larger than that of the inner layer, and which is formed of tempering martensite. A raceway portion of the surface layer part a portion that is in contact with at least one end of the rolling contact surface of the roller in an axial direction, and includes a first raceway portion at which compressive residual stress of the raceway surface is relatively high.

A bearing ring for a roller bearing includes: an inner layer part that is formed of tempering martensite or sorbite; and a surface layer part that surrounds the entire periphery of the inner layer part, in which Vickers hardness of a surface thereof is larger than that of the inner layer, and which is formed of tempering martensite. A raceway portion of the surface layer part a portion that is in contact with at least one end of the rolling contact surface of the roller in an axial direction, and includes a first raceway portion at which compressive residual stress of the raceway surface is relatively high.

An oil-immersion quenching cooling precursor and an oil-immersion quenching cooling method includes an axle-type workpiece or a workpiece that has sections in an axle form. Several separation rings are arranged on the workpiece in the axial direction to separate the axle-type workpiece or the workpiece that has sections in an axle form into a plurality of sections before oil-immersion quenching cooling. In the method, there is a cutting procedure before a quenching cooling procedure. Several separation rings distributed in the axial direction are reserved outside a dimension required for the workpiece. sections before oil-immersion quenching cooling. In the method, there is a cutting procedure before a quenching cooling procedure. Several separation rings distributed in the axial direction are reserved outside a dimension required for the workpiece.

A cooling tank for the thermal treatment of a rail head provided with a structure comprising a first volume (2), adapted to be filled with a cooling fluid; a second volume (4), arranged above the first volume and communicating therewith, so that the fluid passes from the first to the second volume and the rail head to be thermally treated can be immersed therein; a partition plate (5) between first and second volume, provided with a single row of holes (6), preferably arranged at the center of the width of the second volume, for generating jets of cooling fluid from the first to the second volume; a pair of longitudinal bulkheads (7), arranged in said second volume perpendicular to the plate and symmetrically with respect to the single row of holes, adapted to direct the jets of fluid exiting from the holes vertically upwards.

A cooling tank for the thermal treatment of a rail head provided with a structure comprising a first volume (2), adapted to be filled with a cooling fluid; a second volume (4), arranged above the first volume and communicating therewith, so that the fluid passes from the first to the second volume and the rail head to be thermally treated can be immersed therein; a partition plate (5) between first and second volume, provided with a single row of holes (6), preferably arranged at the center of the width of the second volume, for generating jets of cooling fluid from the first to the second volume; a pair of longitudinal bulkheads (7), arranged in said second volume perpendicular to the plate and symmetrically with respect to the single row of holes, adapted to direct the jets of fluid exiting from the holes vertically upwards.

A process for recycling aqueous quenching fluids, said process comprising: (a)(1) providing a metal quenching bath tank comprising a used metal aqueous quenching fluid containing contamination with a water insoluble, fire resistant hydraulic fluid; or (a)(2) collecting, in a collection tank in association with a quench barrel or quench ring, used metal aqueous quenching fluid after the fluid has been sprayed onto heated metal, wherein the collected used fluid is contaminated with a water insoluble, fire resistant hydraulic fluid; (b) heating the bath tank (a)(1) or collection tank (a)(2) to a temperature of about 105 to 200 F. with agitation for less than 12 hours; (c) recovering a resulting uncontaminated aqueous quenching phase from a lower portion of the bath tank (a)(1) or collection tank (a)(2); and (d) returning the recovered aqueous quenching phase to a functional quenching bath tank or functional quenching spray tank.

A process for recycling aqueous quenching fluids, said process comprising: (a)(1) providing a metal quenching bath tank comprising a used metal aqueous quenching fluid containing contamination with a water insoluble, fire resistant hydraulic fluid; or (a)(2) collecting, in a collection tank in association with a quench barrel or quench ring, used metal aqueous quenching fluid after the fluid has been sprayed onto heated metal, wherein the collected used fluid is contaminated with a water insoluble, fire resistant hydraulic fluid; (b) heating the bath tank (a)(1) or collection tank (a)(2) to a temperature of about 105 to 200 F. with agitation for less than 12 hours; (c) recovering a resulting uncontaminated aqueous quenching phase from a lower portion of the bath tank (a)(1) or collection tank (a)(2); and (d) returning the recovered aqueous quenching phase to a functional quenching bath tank or functional quenching spray tank.

In some examples, an apparatus includes a pallet supporting a plurality of workpieces, the pallet including through-holes structured to pass a quenching fluid. In some examples, the apparatus further includes a reservoir of quenching fluid configured to provide the quenching fluid, and a plurality of upturned wall portions extending from the pallet and substantially surrounding the exteriors of the plurality of workpieces. The plurality of upturned wall portions may be located in relative orientation to the plurality of workpieces to regulate heat transfer coefficients of the plurality of workpieces during a quenching operation.

In some examples, an apparatus includes a pallet supporting a plurality of workpieces, the pallet including through-holes structured to pass a quenching fluid. In some examples, the apparatus further includes a reservoir of quenching fluid configured to provide the quenching fluid, and a plurality of upturned wall portions extending from the pallet and substantially surrounding the exteriors of the plurality of workpieces. The plurality of upturned wall portions may be located in relative orientation to the plurality of workpieces to regulate heat transfer coefficients of the plurality of workpieces during a quenching operation.