Effect of honing gear hardness on microgeometry and surface quality improvement of straight bevel gears in PECH process

摘要

The present research is directed to investigate pulsed electrochemical honing (PECH) of bevel gears. Honing gears made of 20MnCr5 alloy steel were case hardened (found to have Vicker's hardness value as 900 HV) using glow discharge plasma nitriding process. The hardened honing gear was used to finish workpiece gear made of same material. Unhardened honing gear having Vicker's hardness value as 630 HV was also used to finish workpiece gears for comparison. The microgeometry of the workpiece bevel gear was evaluated using deviations in pitch, run-out and topology, while surface quality was evaluated in terms of surface finish, microstructure and microhardness. This research proves that the honing gear hardness is an important aspect for improving the surface quality and microgeometry of the gears. These improvements will enhance service life and operating performance of the PECH-finished gears and will reduce their noise level and chances of their premature failures.