STRESS RELIEF OF GRAY CAST IRON
Abstract
The report describes a number of experiments on the stress relief of gray cast iron. One set of experiments consisted of making relaxation tests and using the rate of relaxation as a means of evaluating stress relief. These studies showed that: (1) the rate of stress relief is most rapid during the first hour at temperature; (2) the rate of stress relief is very slow below 1000 F, but increases as the temperature is raised; and (3) initial stress and alloy composition have an important influence on the rate of stress reduction by heat treatment. Observations of heat treatments on highly stressed cast wheels revealed that (1) indoor aging and low-temperature (600 F) heat treatment are ineffective for stress relieving, (2) furnace cooling after heat treatment produces lower residual casting stresses than air cooling, and (3) relaxation tests agree closely with results of stress-relief heat treatments of experimental castings.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 09, 1948
- Accession Number
- AD0620556
Entities
People
- J. H. Schaum
Organizations
- United States Naval Research Laboratory