Investigation on Residual Stress Induced by Shot Peening

• Published in: Journal of materials engineering and performance Vol. 24; no. 3; pp. 1340 - 1346
• Main Authors: Zhao, Chunmei, Gao, Yukui, Guo, Jing, Wang, Qiang, Fu, Lichao, Yang, Qingxiang
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-03-2015
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology; residual stress; steel; X-ray
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-014-1382-0

The high strength steel widely used in the aviation industry was chosen in this paper. The shot peening (SP) tests with different technical parameters were carried out, and compressive residual stress (CRS) distribution along the depth was determined. The phase structures before and after SP were analyzed by XRD and TEM. Microhardness and fatigue life were measured, and the morphology of fatigue fracture was also observed. The effects of different technical parameters on CRS field were investigated, and the CRS features with the characteristic parameters were analyzed deeply to summarize the rules. The results show that the CRS field induced by SP can be expressed by four characteristic parameters: the surface CRS σ
srs
, the maximum CRS σ
mrs
, the depth of maximum CRS ξ
m
and the depth of CRS (strengthened depth) ξ
0
. Martensite matrix is not changed by SP, while its boundary changes ambiguous with the formation of dislocations. After SP, the microhardness of the specimen increase, and the fatigue crack source moves inwards. The SP saturated time is 1 min. With the increase of SP intensity, σ
srs
, σ
mrs
, ξ
m
, and ξ
0
all increase. While with the increase of SP angle, ξ
0
grows gradually. The strengthen effect behaves more obviously as the shot size increases, and the shot material with larger hardness cause higher level of CRS field. Dual SP mainly increases σ
srs
value.