Fatigue Crack Propagation for Cast Iron Rotating Disk

This paper studies the crack propagation rate for three kinds of cast iron rotating disks. Fatigue crack propagation tests were carried out for flake, compacted vermicular and spheroidal graphite cast iron disks under repeated spin loading. The crack propagation rate of the flake graphite disk was the largest, while that of the spheroidal graphite disk was the smallest. The crack propagation rate of the compacted vermicular graphite disk had the intermediate crack propagation rate between the two cast iron disks. The stress intensity factor range could not correlate the crack propagation rate for the three kinds of disks, while the J-integral range, which was calculated in finite-element analyses, could correlate the crack propagation rate within a factor of five scatter bands. The stress intensity factor range modified by the tensile strength of the material was also effective for correlating the crack propagation rate for three kinds of cast iron.