Precision Gear Profile with Chromium Alloyed Steel
A preform of 1.5Cr-0.2Mo PM steel having density of 7.55 g/cc was surface rolled using a high precision transverse rolling machine to form a spur gear. The rolling was designed to get good surface densification and tight tolerances on the gear profile. After rolling, casehardening was conducted. Pore distribution and endurance limits in both bending fatigue and rolling contact fatigue were investigated. The results support the feasibility of using transverse rolling of high density P/M materials to obtain high precision spur gears with strength comparable to wrought steel.