Environmental Hydrogen Cracking of HY Steel Weld Metals.
Abstract
Techniques used in a program to develop HY steel weld metals with improved resistance to environmental hydrogen cracking include (1) levitation melting and chill casting of Charpy-size specimens, and (2) accelerated environmental testing by the H2S rising-load method. The measured values of K(or), the stress intensity of crack-growth onset, had satisfactory reproducibility as well as sensitive response to composition. However, K(or) is larger than the threshold stress intensity K(arr) (or K(Iscc)) by an amount that varies directly with t(io), the incubation-time constant. Since t(io) is short relative to design life, only k(arr) has design significance. Two new accelerated methods of determining K(arr) are (1) a modified rising-load test in which the displacement is held constant after crack-growth onset, and (2) a similar procedure substituting environmental fatigue precracking for the rising-load phase. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 15, 1979
- Accession Number
- ADA074104
Entities
People
- B. J. Shaw
- E. W. Johnson