THE EFFECT OF STRUCTURAL TRANSFORMATIONS ON THE RELAXATION STABILITY OF AUSTENITIC STEELS AND ALLOYS,
Abstract
The effect of structural changes (caused by volume reduction) on stress relaxation when the specimen length remains constant is examined. Relaxation curves of heat-resistant austenitic steel are compared with data from phase analysis. Steels 1Kh18N9T, Kh15N15V5T, EI164, and Kh15N65VMTYu are considered. The latter steel was tested for relaxation for 20,000 hr at 750C and at initial stresses of 200, 250, 300, and 350 MN/sq m (or at 33, 40, 45, 50, and 60 percent of the mean yield point at 750C). The steel was air hardened from 1080C and tempered for 16 hr at 800C. Two periods of stress relaxation were observed. After the first period (300-500 hr), the remaining stress was about 0.7 of the initial. In the second period, relaxation was less intensive. Greatly hardened alloys containing 25-40 percent secondary phases are considered to be completely unsuitable for long-term service under relaxation conditions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 06, 1969
- Accession Number
- AD0700403
Entities
People
- A. M. Borzdyka
Organizations
- National Air and Space Intelligence Center