THE RESISTANCE OF HEAT-RESISTANT ALLOYS TO THERMAL FATIGUE AS A FUNCTION OF THERMAL STRESS,
Abstract
To study the effects of varying heat stresses on machine parts during starting and when changing operating regimes, investigations were made of heat-resistant EI437B, EI617, EI867, and EP109 alloy specimens under loads, using the Koffin-type setup. The greatest reduction in the number of cycles was observed during the maximum-temperature periods which measured 1.5 min. As the cycle length increased further, the effect became smaller. It is, therefore, possible to assume that the damage occuring during the maximum-temperature period, takes place in the specimen mainly during the first stage of the constant-temperature application. Damage is due to creep and redistribution of stresses which develop during the maximum-temperature period. As a result of the damage, the number of cycles preceding breakdown decreased but the total length of time before breakdown remained little affected. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 25, 1969
- Accession Number
- AD0695193
Entities
People
- R. A. Dulnev
Organizations
- National Air and Space Intelligence Center