STRESS-CORROSION CRACKING BEHAVIOR OF AN 18% Ni MARAGING STEEL
Abstract
Stress-corrosion cracking of an 18% Ni maraging steel in aqueous solutions was studied using precracked cantilever beam specimens. By appropriate heat treatments, six different structures having the same yield strength were obtained. Although significantly different plane strain fracture toughness values (K sub Ic) resulted, it was found that the threshold plane strain stress intensity (K sub Iscc) was the same for all structures. K sub Iscc had the same value in 3% NaCl at various pH values, in IN H2SO4, and in distilled water. Specimens tested in 3% NaCl under both anodic and cathodic applied potentials also exhibited this same K sub Iscc value. Fractographic inspection of the crack surfaces revealed no apparent differences due to changes in solution, pH, or applied potential. The crack path was intergranular in all cases. However, specimens austenitized at 1500 F exhibited crack branching, whereas in specimens austenitized at much higher temperatures branching no longer occurred. Aging time and temperature seemed to change only the time to failure. The mechanism most consistent with all observations appears to be hydrogen cracking.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1970
- Accession Number
- AD0704174
Entities
People
- A. J. Stavros
- H. W. Paxton
Organizations
- Carnegie Mellon University