Effect of Spraybond Coating on the Tension-Tension Fatigue Properties of AISI 4340 Steel,
Abstract
An investigation was conducted to determine the effects of the flame sprayed molydenum Spraybond coating on the tension-tension fatigue properties of 4340 steel at the 240 - 260 ksi strength level. Because of the harmful overheating inherent in the Spraybond process, the original 255 ksi tensile strength level of the coated specimens was reduced to approximately 180 ksi. Some tests were conducted atbthe reduced strength level (overheated specimens) and an increase in fatigue life was noted for the unpeened and peened specimens, as compared to the life of the bare tempered control specimens (180 ksi). However, the validity of the results were in question, since establishing the actual strength level of each coated specimen would have required destructive tests, which was obviously impossible. It is important to emphasize the need for avoiding incidental harmful overheating of steel parts when applying Spraybond or any other flame sprayed metallic coating for 'build-up' of worn or undersized components, particularly when components are small in size, and fatigue and retention of tensile strength are critical considerations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 18, 1971
- Accession Number
- AD0729290
Entities
People
- Joseph Viglione
- Walter F. Worden
Organizations
- Naval Air Warfare Center Warminster