METHOD OF THERMAL TREATMENT OF HIGH-PRECISION PARTS OUT OF SPRING SILICON STEELS Russian patent published in 2015 - IPC C21D9/02 C21D9/40 

FIELD: machine building.

SUBSTANCE: sheets are manufactured out of steel 65C2BA, charge of sheets is assembled, and isothermal hardening with holding at isotherm temperature is performed in niter, tempering, hardness testing, dimensions and cracks control are performed, at that the sheets charge is assembled in packages, the assembled packages are located on the carrying device in form of the bar, to which the rods are welded perpendicular and symmetrically to it, the carrying device with charge is heated in the furnace at 200-400°C, then the charge is heated for hardening with sheets holding at isotherm temperature 300-340°C for 30 minutes, and tempering is performed at 300-340°C, at that in each sheet two holes are made, and sheets are assembled in packages with assurance of the permanent gaps by means of the bushings - gaskets through the said holes on wire, which diameter corresponds to the sheet holes diameter. To reduce the cooling rate during the isothermal holding each sheet is located between the thin screens.

EFFECT: assurance of the accurate geometric parameters of springs and complete elimination of cracks.

2 cl, 3 dwg