scholarly journals Cyclic fatigue-crack propagation in a silicon carbide whisker-reinforced alumina composite: role of load ratio

1993 ◽  
Vol 28 (12) ◽  
pp. 3258-3266 ◽  
Author(s):  
R. H. Dauskardt ◽  
B. J. Dalgleish ◽  
D. Yao ◽  
R. O. Ritchie ◽  
P. F. Becher
Keyword(s):  
Silicon Carbide ◽  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Load Ratio ◽  
Cyclic Fatigue ◽  
Silicon Carbide Whisker ◽  
Alumina Composite

scholarly journals Effect of Solution Annealing on Fatigue Crack Propagation in the AISI 304L TRIP Steel

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1331
Author(s):  
Michal Jambor ◽  
Tomáš Vojtek ◽  
Pavel Pokorný ◽  
Miroslav Šmíd
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Load Ratio ◽  
Load Shedding ◽  
Shielding Effect ◽  
Trip Effect ◽  
Aisi 304L ◽  
Crack Tip Shielding

Fatigue crack propagation in near-threshold regime was studied in the 304L austenitic stainless steel in two microstructural states: as-received (AR) with finer microstructure and low susceptibility to the transformation-induced plasticity (TRIP) effect, and solution-annealed (SA) with coarser microstructure and higher susceptibility to TRIP. At the load ratio R = 0.1 the threshold was higher in the SA state than in the AR state due to coarser grains and possibly the TRIP effect. In order to clarify the role of crack closure, experiments at R = 0.7 were done. The threshold in the SA state was still higher by 1 MPa·m0.5. This effect was identified as crack tip shielding induced by phase transformation, an example of a non-closure shielding effect. Higher resistance to crack growth in the SA state was attributed to promoted martensitic transformation in non-favorable oriented grain families rather than thicker martensite layers in the crack path area. The conclusions were verified by experiments at R = 0.7 and temperature 150 °C > Ms which did not reveal any notable difference in thresholds. However, the threshold values were affected by the load-shedding gradient C = −dΔK/da, which had to be equalized in both experimental setups inside and outside the furnace.

Sign in / Sign up

Export Citation Format

Share Document