November_December_2021_AMP_Digital

FEATURE A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 2 1 4 8 however batch A gears did not. The topography of tooth profile is shown in Fig. 3. CONCLUSIONS Testing of two batches of hypoid gear sets shows that the annealing heat treatment intro- duced between gear set soft cutting and case car- burizing helped tominimize the distortion. The re- sidual stress analysis shows the variation in stress level within the part and part-to-part variation. The analysis after annealing shows the machining tensile residual stresses induced are relieved by annealing. This is evidenced by the gear set profile inspection carried out using Klingelnberg equip- ment. The tooth topography of batch B shows less dimensional imperfection by qualifying AGMA class 8 than batch A, which is evidence of the con- tribution of annealing in controlling the distortion of gear sets. ~HTPro For more information: Yathish Rao, industry pro- fessional, Pune, India, rao.yathish@gmail.com . References 1. Heat Treating, Vol 4, ASM Handbook, ASM International, 1991. 2. Metallography and Microstructures, Vol 9, ASM Handbook, ASM International, 2004. 3. Materials Characterization, Vol 10, ASM Hand- book, ASM International, 2019. 11 Fig. 3 — Batch A topography of a tooth (top). Batch B topography of a tooth (bottom). Batch B is superior to batch A. Fig. 2 — Annealing process improvement. Batch B is superior to batch A gear sets. 14