R. Sandhya et al., The effect of coldwork on the Low Cycle Fatigue and Creep-Fatigue Interaction properties of Alloy D9, T I INST ME, 53(3), 2000, pp. 273-276
Alloy D9, a 15Cr-15Ni, Ti modified stainless steel is a candidate material
for fast reactor core components due to its excellent resistance to void sw
elling. The alloy with Ti/C ratio of 4 has been investigated For its Law Cy
cle Fatigue(LCF) and Creep-Fatigue Interaction (CFI) properties in solution
annealed and 20% cold worked condition. LCF tests have been conducted in a
ir at 823K and 923K, while CFI tests were performed at 923K using holds at
peak tensile strain. Under continuous cylcing LCF conditions, solution anne
aled material exhibited superior LCF resistance than cold worked material a
t both 823 and 923K, except at low strain ranges at 923K. The solution anne
aled material underwent cyclic hardening while cold worked material display
ed cyclic softening. Under CFI conditions, solution annealed material exhib
ited a recovery in life at longer hold times, while coldworked material exh
ibited a continuous decrease in life with increasing hold time. The LCF and
CFI properties have been correlated with the substructural recovery and pr
ecipitation at these temperatures.