Accession Number : AD0729290

Title :   Effect of Spraybond Coating on the Tension-Tension Fatigue Properties of AISI 4340 Steel,

Corporate Author : NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AERO MATERIALS DEPT

Personal Author(s) : Viglione,Joseph ; Worden,Walter F.

Report Date : 18 MAY 1971

Pagination or Media Count : 14

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)

Descriptors :   (*STEEL, FATIGUE(MECHANICS)), (*FLAME SPRAYING, STEEL), METAL COATINGS, MOLYBDENUM

Subject Categories : Coatings, Colorants and Finishes
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE