Floorplanning

The influence of microstructure on the fatigue crack growth rate in marine steels in the Paris Region

“…There are many studies that claimed that microstructure has negligible effect at intermediate FCGRs (Paris Region). 3,5,6,[13][14][15][16]20 Some other study concluded that grain size affected subcritical crack growth to the extent to which it affected fracture toughness, K Ic and the onset of rapid fracture and that grain size did not affect the FCG threshold, ΔK th. 4 Zerbst 6 in his recent publication reported that '… Perhaps the most astonishing observation is that the curve, in the Paris Region, is only slightly influenced by the microstructure of the material within whole material classes such as steels or aluminium alloys.'…”

“…These factors were reported to have little or negligible effects when the propagating crack has grown to a considerable length or beyond few grains, usually in the Paris Region. 5,[11][12][13][14][15][16] In the threshold region, non-continuum or single shear mechanism is said to operate and the nature of the fractured surface is seen to be faceted. The crack tip was under both tensile and shear forces.…”

The Influence of Microstructure on the Fatigue Crack Growth Rate in ferrite-pearlite Steels in the Paris Region

“…In addition, the accelerated region is said to be influenced by sample thickness. These factors were reported to have little or negligible effects when the propagating crack has grown to a considerable length or beyond few grains, usually in the Paris Region [5] [9][10] [11] [12] [13] [14]. In the threshold region, non-continuum or single shear mechanism is said to operate and the nature of the fractured surface is seen to be faceted.…”