Stability of shot peening induced residual stresses and their influence on fatigue lifetime

• Mechanical surface treatment methods such as shot peening may improve the fatigue strength of materials. In this study, the effect of shot peening on strain controlled constant amplitude fatigue loading of a near pearlitic microalloyed steel was investigated. The stress amplitudes throughout the whole lifetime were followed, in addition to detailed recording of stress-strain hysteresis loops, particularly at small cycle numbers. The detailed relaxation of residual stresses and the changes in full width of half maximum (FWHM) of the X-ray peak at the surface and in depth as function of the number of cycles and plastic strain were recorded. By these techniques, the onset as well as the rate of relaxation of residual stresses could be followed at different strain amplitudes. Pronounced increase in lifetime of the shot peened specimens tested at total strain amplitude smaller than 0.3% (corresponding to 0.034% plastic strain amplitude) was achieved. This coincides with reasonably stable residual stresses at the surface and in depth. © 2010 Elsevier B.V.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Produktionsteknik, arbetsvetenskap och ergonomi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Production Engineering, Human Work Science and Ergonomics (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

Fatigue

Micro alloyed steel

Relaxation

Residual stress

Work hardening

Alloyed steels

Constant amplitude

Cycle number

Fatigue lifetime

Fatigue loadings

Full width of half maximum

Mechanical surface treatment

Microalloyed Steel

Number of cycles

Plastic strain

Rate of relaxation

Strain amplitude

Stress amplitudes

Stress-strain hysteresis loops

Total strain amplitude

X-ray peaks

Building materials

Fatigue of materials

Hysteresis

Hysteresis loops

Plastic deformation

Shot peening

Strain hardening

Surface treatment

Residual stresses

Manufacturing engineering

Produktionsteknik

Manufacturing and materials engineering

Produktions- och materialteknik

Publication and Content Type

ref (subject category)

art (subject category)