Effect of Normalized Microstructure in Alloy Steel on the Performance of Planetary Gear Set of Automatic Transmission Hyundai Motor Company

Format:

Conference/Event

Author/Creator:

Jung, Seung Cheal, author.

Conference Name:

SAE International Congress & Exposition (1997-02-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 1997

Summary:

The banded microstructure of pearlite and ferrite in normalized alloy steel is susceptible to thermal distortion during carburizing process due to its unidirectional orientation parallel to rolling direction. The planetary gears with material of banded microstructure have been experienced in high thermal distortion during carburizing and quenching process and result in uneven surface hardness and effective case depth at the inside of pinion gear after honing. These defects played failure initiation site roles in durability test during development of new automatic transmission. The galling between the contacting components in severe lubricating system was the main failure mechanism. Double normalizing at 920 °C was designed to resolve the banded microstructure of normalized alloy steel. The microstructure and grain size of the double heated steel became equiaxed and fine due to homogenizing and recrystallization through double heat treatment. The thermal distortion and subsequent surface properties at the inside of pinion gear were also improved. Finally the durability of the planetary gear set at maximum speed test is enhanced by 2.91 times

Notes:

Vendor supplied data

Publisher Number:

970972

Access Restriction:

Restricted for use by site license