Effect of Surface Residual Stress and Inclusion Size on Very High Cycle Fatigue Properties of High Speed Tool Steel

Gigacycle fatigue in high strength steels

“…A problem with the Tanaka-Akiniwa model is the validity of the calculated internal crack growth rates. As suggested in the discussion on crack initiation being dominant, extremely slow crack growth rates, which are much smaller than the lattice length, are yielded when the Tanaka-Akiniwa model is applied to gigacycle fatigue [71][72][73]. The Tanaka-Akiniwa model, therefore, needs experimental confirmation of the existence of this extremely slow crack growth.…”

Influences of Manufacturing‐Related Microstructural Variations on Fatigue in Carbide‐Rich Tool Steels

“…Extensive investigations of the VHCF properties of various highstrength steels under cantilever-type rotating bending and axial loading were performed by Shiozawa et al, [27][28][29][30][31] Lu et al, [32,33] and Shimatani et al [34][35][36][37] The information provided in literature can contribute in the following to a deeper classification and understanding of fatigue in high-strength and high-hardness steels.…”

“…[12,25,26] In addition, surface conditions and treatments can affect the fatigue performance of tool steels, e.g., different hard machining and polishing processes or surface treatments and finishing techniques. [17,20,26,[33][34][35][36][37] Sohar et al [13][14][15][16][17][18][19][20] focused on the effects of manufacturing, carbide microstructure and compressive residual stresses (CRS) on the UHCF strength and failure mechanisms. They separate three different failure modes for ingot cast tool steels depending on the present residual stresses at the specimen surface.…”

“…[33,39] When surface treatments that created additional CRS such as plasma nitriding or shot peening are applied, the surface failure mode is shifted to higher cycle numbers and the appearance of the duplex S-N curves can change depending on this modified surface failure mode. [33] Shimatani et al [34][35][36][37] also distinguished between a surface failure mode (S) and two internal volume failure modes with GBF area formation (IG) and without GBF (I) similar to studies by Shiozawa et al [27][28][29][30][31] and Lu et al [32,33] Shimatani et al [34] reported duplex S-N curves under rotating bending and axial loading for high speed steels, whereby the transition stress amplitude of the failure modes is different for both loading types and can be explained by transition diagrams accounting the introduced surface CRS. [34,35] Shimatani et al [36,37] confirmed that, in accordance with studies by Sohar et al, [13,14,17,20] a large CRS is occuring at the early stages of fatigue cycling and CRS subsequently decrease to an almost constant value in VHCF and UHCF after a certain fatigue life ratio.…”

“…[33] Shimatani et al [34][35][36][37] also distinguished between a surface failure mode (S) and two internal volume failure modes with GBF area formation (IG) and without GBF (I) similar to studies by Shiozawa et al [27][28][29][30][31] and Lu et al [32,33] Shimatani et al [34] reported duplex S-N curves under rotating bending and axial loading for high speed steels, whereby the transition stress amplitude of the failure modes is different for both loading types and can be explained by transition diagrams accounting the introduced surface CRS. [34,35] Shimatani et al [36,37] confirmed that, in accordance with studies by Sohar et al, [13,14,17,20] a large CRS is occuring at the early stages of fatigue cycling and CRS subsequently decrease to an almost constant value in VHCF and UHCF after a certain fatigue life ratio. The fatigue strength of carbide-rich tool steels under rotating bending from studies by Shimizu et al, [40] Randak et al, [41] and Broeckmann et al [42] is shown in Figure 1.…”