The bending fatigue strength of gears in isotropic 20NiMo10 steel in as-machined, single-peened and double-peened condition

Abstract

Abstract The bending fatigue strength of case-hardened pulsator test gear wheels has been investigated for wheels in fatigue isotropic 20NiMo10 (Ovako 158Q) steel. The pulsator gears where either in un-peened (but shot-cleaned), single shotpeened or double shot-peened condition. Single shot peening increased the bending fatigue strength of the gears by some 11 per cent as compared with the un-peened. Double shotpeening was not successful and did not result in any further increase of bending fatigue strength. That was explained with wrongly chosen parameters of the second shot peening moment and therewith over-peening of the component. That second moment was a trial and had never been tested before. 20NiMo10 can be used on current production lines and can be case-hardened in current production furnaces. If availability of the steel is guaranteed, 20NiMo10 has the potential to replace current production material.