Improvement in surface fatigue life of hardened gears by high-intensity shot peening

Conference · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7305040

Townsend, D P

Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 7305040
• Report Number(s): N-92-26108; NASA-TM-105678; E-6986; NAS-1.15:105678; AVSCOM-TR-91-C-042; CONF-9209167-; CNN: DA PROJ. 1L1-62211-A-47-A; RTOP 505-63-36
• Resource Relation: Conference: 6. international power transmission and gearing conference, Scottsdale, AZ (United States), 13-16 Sep 1992; Other Information: Sponsored by ASME
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
GEARS
FATIGUE
SHOT PEENING
CORRELATIONS
DEPTH
LUBRICANTS
MATERIALS TESTING
OILS
RESIDUAL STRESSES
SERVICE LIFE
STEELS
STRESS INTENSITY FACTORS
SURFACE FINISHING
ALLOYS
COLD WORKING
DIMENSIONS
FABRICATION
IRON ALLOYS
IRON BASE ALLOYS
LIFETIME
MACHINE PARTS
MATERIALS WORKING
MECHANICAL PROPERTIES
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
STRESSES
SURFACE TREATMENTS
TESTING
420500* - Engineering- Materials Testing
360101 - Metals & Alloys- Preparation & Fabrication
360103 - Metals & Alloys- Mechanical Properties