Accession Number:

AD0763900

Title:

Thermal Embrittlement of 4340 Steel

Descriptive Note:

Technical rept.

Corporate Author:

ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MA

Personal Author(s):

Report Date:

1972-12-01

Pagination or Media Count:

19.0

Abstract:

OF 1000 F within 16 days. The degree of embrittlement depended on both time and temperature. Reductions in toughness were correlated with changes in the morphology and size of ferrite grains as well as the size of carbide particles. These microstructural changes were similar to those observed in both 3140 and plain carbon steels by other investigators. Conventional anisothermal procedures used to produce temper brittleness in low alloy steels also embrittle these steels by another mechanism. Thus, the degradation of toughness attributed to temper brittleness results from two different modes of embrittlement. Transitional behavior previously described as the retrogression of temper brittleness is concluded to result from thermal embrittlement. Author

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE