STRAIN HARDENING OF PARTS AT HIGH TEMPERATURES UNDER ASYMMETRIC LOADS,
Abstract
Results are presented of an investigation of the effectiveness of surface strain hardening to increase the fatigue strength of turbine-blade roots at high temperatures under asymmetric loads. The following data on thermal treatment of samples are given: (a) EI726 steel-austentizing, 1140-1160 degrees; air-cooling and aging, 750 degrees for 25 hrs; (b) EI481 steel-hardening, 1050-1100 degrees, 1 hr plus 1140-1150 degrees, 1 hr 30 min. of water quenching; aging, 670 degrees, 12 hr plus 790 degrees and 12 hrs of air-cooling. The investigation was begun by selecting strain-hardening regimes, and then the strain-hardening levels of the above-mentioned investigated steels were determined. The effectiveness of the strain-hardening treatment was checked by comparative fatigue tests using a YA8M machine. Tests were carried out under symmetric cyclic loads at room and operating (500 degrees) temperatures. The experiments are described and a table is presented giving the chemical compositions above steels. The experimental results were verified by using them to calculate a real blade root of the GT-700-5 NZL turbine. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1969
- Accession Number
- AD0694401
Entities
People
- G. Z. Zaitsev
- L. R. Alishoev
- S. V. Kudryavtseva
Organizations
- National Air and Space Intelligence Center