Effect of second phase on the fatigue crack growth in AlSl 4340 steel

Development of a Novel Approach for Fatigue Life Prediction of Structural Materials

“…The effect of type and fraction of secondary phase on the fatigue crack growth behavior of 4340 steel was experimentally studied by Hwang et al [47]. The second phase in the alloy produced by different types of heat treatment can be bainite or tempered martensite.…”

Effects of a laser surface processing induced heat-affected zone on the fatigue behavior of AISI 4340 steel

“…If the cooling rate of the HAZ is too slow, low-alloys steels like AISI 4340 are vulnerable to tempered martensite embrittlement, which could lead to a loss of fracture toughness and fatigue resistance [8]. Not all materials behave the same, however, Hwang et al [9,10] found that the HAZ exhibited greater fatigue crack growth resistance than the substrate material in a cold-rolled steel, and attributed it to refinement in the microstructure of the welded zone. Tsay et al [11] found similar results for D6AC steel, a high-strength, medium-carbon, low-alloy steel, and attributed it to the presence of lower bainite and tempered martensite in the microstructure of the weld region and the HAZ.…”

Effects of size and spacing of uniformly distributed pearlite particles on fatigue crack growth behavior of ferrite–pearlite steels

“…If the effect of microstructure on fatigue crack growth resistance in the Paris regime could be made clear in detail, fatigue crack growth resistance could be improved by controlling the microstructure. Although only limited information is available on the detailed influence of microstructure on fatigue crack growth resistance in the Paris regime, some important works on fatigue crack growth behavior of two phase steels have been reported [5,7,[14][15][16][17][18][19][20][21][22][23][24].…”