Fatigue limit of chemical heat treated specimens and effect of shot peening

2008 ◽  
Vol 24 (5) ◽  
pp. 322-326 ◽  
Author(s):  
Y.-K. Gao
Keyword(s):  
Fatigue Limit ◽  
Shot Peening ◽  
Chemical Heat ◽  
Heat Treated

Fully Reversed Uniaxial Tension-Compression High Cycle Fatigue Behaviour of Shot-Peened Steels

2011 ◽  
Vol 488-489 ◽  
pp. 21-24
Author(s):  
Alan Plumtree ◽  
M. M. Mirzazadeh
Keyword(s):  
Fatigue Limit ◽  
Shot Peening ◽  
Surface Hardness ◽  
Fatigue Behaviour ◽  
Cyclic Softening ◽  
Beneficial Effects ◽  
Heat Treated ◽  
Quenched And Tempered Steel ◽  
Hot Rolled ◽  
Compressive Residual Stresses

The effect of shot-peening on the uniaxial fatigue behaviour of four engineering steels, heat treated to a similar final hardness was investigated. Forged 0.39%C and 0.72%C steels, a quenched and tempered 0.51%C steel and a 0.50%C powder forged (PF) steel were fatigue tested under fully reversed (R=-1) push-pull loading conditions. Following long life (107) cycling, shot-peening had little effect on the fatigue limit of the 0.39%C and 0.72%C steels whereas the fatigue limit of the PF steel increased 10.4%. Conversely, the fatigue limit of the quenched and tempered steel decreased 12.0% after shot-peening. The results showed that the beneficial effects of shot-peening, such as compressive residual stresses and work hardening, balanced the effects of surface roughness since crack initiation tended to occur below the surface. Microhardness profiles showed that the greatest amount of cyclic softening in the shot-peened regions occurred in the hot rolled steels. Softening was accompanied by a decrease in the depth of surface hardness.

scholarly journals The Effect of Baking Heat Treatment on the Fatigue Strength and Life of Shot Peened 4340M Landing Gear Steel

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5711
Author(s):  
Seok-Hwan Ahn ◽  
Jongman Heo ◽  
Jungsik Kim ◽  
Hyeongseob Hwang ◽  
In-Sik Cho
Keyword(s):  
Heat Treatment ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Shot Peening ◽  
High Cycle Fatigue ◽  
Landing Gear ◽  
Cycle Fatigue ◽  
Heat Treated ◽  
Ultrasonic Fatigue

In this study, the effect of baking heat treatment on fatigue strength and fatigue life was evaluated by performing baking heat treatment after shot peening treatment on 4340M steel for landing gear. An ultrasonic fatigue test was performed to obtain the S–N curve, and the fatigue strength and fatigue life were compared. The micro hardness of shot peening showed a maximum at a hardened depth of about 50 μm and was almost uniform when it arrived at the hardened depth of about 400 μm. The overall average tensile strength after the baking heat treatment was lowered by about 80–111 MPa, but the yield strength was improved by about 206–262 MPa. The five cases of specimens showed similar fatigue strength and fatigue life in high cycle fatigue (HCF) regime. However, the fatigue limit of the baking heat treated specimens showed an increasing tendency rather than that of shot peening specimens when the fatigue life was extended to the very high cycle fatigue (VHCF) regime. The effect of baking heat treatment was identified from improved fatigue limit when baking heat was used to treat the specimen treated by shot peening containing inclusions. The optimum temperature range for the better baking heat treatment effect could be constrained not to exceed maximum 246 °C.

scholarly journals Increase in Fatigue Limit of Gears by Compound Surface Refining Using Vacuum Carburizing, Contour Induction Hardening and Double Shot Peening

2002 ◽  
Vol 45 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Katsuyuki MATSUI ◽  
Hirohito ETO ◽  
Katsuya YUKITAKE ◽  
Yoshitaka MISAKA ◽  
Kotoji ANDO
Keyword(s):  
Fatigue Limit ◽  
Shot Peening ◽  
Induction Hardening ◽  
Vacuum Carburizing ◽  
Compound Surface
Sign in / Sign up

Export Citation Format

Share Document