STRESS CORROSION CRACKING CONTROL MEASURES. 5. TITANIUM ALLOYS,
Abstract
The practical SCC hazards to titanium involve a wide range of environments. For some groups of environments, such as natural waters and nearly neutral aqueous solutions, the cracking occurs only in the presence of a pre-existing crack-like flaw, and fracture mechanics type tests readily characterize the SCC behavior of alloys. Unalloyed titanium and the widely used Ti-6%al-4%V alloy are reasonably resistant to SCC in these environments. For N2O4 and red fuming nitric acid, practical control of the problem is available through controlling the composition of the oxidizers, for which standard specifications are available. For the hot salt cracking problem during heat treatment, meticulous cleanliness of the titanium, backed up preferably by excluding moisture and oxygen from the heat treating atmosphere, serves to control the problem. Though untried in practice, a nickel barrier paint may be useful when contamination at elevated temperatures cannot be avoided in service; the alternative is to design for low operating stresses. For some environments, such as methanol, mercury, cadmium or silver, the strategy is to exclude them from titanium surfaces.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1975
- Accession Number
- ADA013612
Entities
People
- B. F. Brown
Organizations
- American University