Effect of surface roughness on the fretting fatigue behaviour of EN45A spring steel

Abstract

Much research has been carried out to improve the fatigue strength of materials in general and leaf springs in particular by creating a compressive residual stress field of their surface layers through shot peening. The phenomenon of surface roughness is important when considering contact between metallic bodies. The effect of shot flowrate on surface roughness was identified. Full-scale laboratory testing of EN45A spring steel leaf springs was carried out using an electrohydraulic testing system to show the extent of improvement in fatigue life due to shot peening. Double shot peening was performed on leaf springs and its effects on surface roughness, compressive residual stress field, and fretting fatigue were noted. The surface roughness model is in accordance with the experimental results.

Keywords

surface roughness leaf springs shot peening fretting fatigue

References

Sharma

M. C.

Improvement of fretting fatigue performance of large steam turbine blade material using ball peening. In Proceedings of the second International Conference on Shot Peening and Blast Cleaning (Ed. Sharma

M.C.

), Bhopal, India, 2001, pp. 120–130.

J. K.

Zhang

Yao

Experimental study of the compressive residual stress field by shot-peening. In Proceedings of the Third International Conference on Residual stresses (ICRS-3), (Ed. Fujiwara

) Tokushima, Japan, 1991, pp. 750–757.

Andrews

Sehitoglu

A computer model for fatigue crack growth from rough surfaces. Int. J. Fatigue, 2000, 22, 619–630.

Waterhouse

R. B.

The effect of surface treatment on the fatigue and fretting-fatigue of metallic materials. In Proceedings of the International Conference on Metal treatments against wear, corrosion, fretting and fatigue (Ed. Waterhouse

R. B.

), Nottingham, UK, 1987, pp. 31–40.

Aggarwal

M. L.

Khan

R. A.

Agrawal

V. P.

Investigation into the effects of shot peening on the fretting fatigue behaviour of 65Si7 spring steel leaf springs. Proc. IMechE, Part I: J. Materials: Design and Applications, 2005, 219, 139–147.

Aggarwal

M. L.

Impact of shot peening parameters on fatigue life of leaf springs. MTech Thesis, Mechanical Engineering Department, Indian Institute of Technology, New Delhi, India, 2003, pp. 30–40.

Shaw

B. A.

Aylott

Hara

P. O.

Brimble

The role of residual stress on the fatigue strength of high performance gearing. Int. J. Fatigue, 2003, 25, 1279–1283.

Torres

M. A. S.

Voorwald

H. J. C.

An evaluation of shot peening, residual stress and stress relaxation on the fatigue life of AISI 4340 steel. Int. J.Fatigue, 2002, 24, 877–888.

Farrahi

G. H.

Lebrun

J. L.

Couratin

Effect of shot peening on residual stress and fatigue life of a spring steel. Fatigue Fracture Engng Mater., 1995, 18(2), 211–220.

10.

Aggarwal

M. L.

Agrawal

V. P.

Khan

R. A.

A stress approach model for predicting fatigue life of EN45A spring steel. Int. J. Fatigue, 2006, (in press).