CRACK INITIATION IN METALLIC MATERIALS.
Quarterly progress rept. no. 3,
SYRACUSE UNIV N Y METALLURGICAL RESEARCH LABS
Pagination or Media Count:
Crack initiation and propagation data for AISI 301 stainless, RS-120 annealed, and PH-15-7Mo in the RH 1050 and the CH-900 conditions under alternating load is presented and analyzed using a new crack propagation law. The constants n and N sub o, relating to crack propagation and initiation resistance which appear in this relation are evaluated for each material and specimen geometry. The constant n is found to be related to the strain hardening coefficient of the material and its values have been found to be a good indication of the materials susceptibility to crack reinitiation. The constant N sub o is found to correspond to the crack initiation times for sharp notch specimens but for the mold notch specimens, the meaning of N sub 0 on the material, the specimen geometry, and the applied stress level is obtained from the test data. Author