THE EFFECT OF INTERSTITIAL ATOM-DISLOCATION INTERACTIONS ON THE DEFORMATION BEHAVIOR OF COLUMBIUM, TANTALUM, AND 1020 STEEL

Technical Report · Mon Jul 31 04:00:00 EDT 1961

OSTI ID:4763997

Wilcox, B A; Huggins, R A

The strain-aging tendencies of arc-melted Nb and Ta, 1020 steel, and hydrogenated Nb were investigated using yield-point return and dynamic modulus of elasticity Measurements to study the aging process. Comparison of activation energies for strain-aging with those for interstitial diffusion revealed that H was responsible for dislocation-locking in Nb, and probably in Ta, in the temperature ranges studied. The studies on 1020 steel reconfirmed the previously well-known fact that N and C cause dislocation-locking in mild steel, and validated the accuracy of the yield-point return and dynamic modulus techniques for studying the strain-aging process. Harper's modification of the Cottrell- Bilby analysis was applied to the dynamic modulus strain-aging data for 1020 steel, Nb, and hydrogenated Nb to determine dislocation densities in these materials. Densities so determined were compared with values obtained by etch- pitting techniques. To obtain a measure of the degree of dislocation-locking in Nb as a function of H content, the lower yield stress of electronbeam-melted Nb was measured as a function of grain size and hydrogen content. (auth)

• Research Organization: Aeronautical Systems Div. Metals and Ceramics Lab., Wright- Patterson AFB, Ohio; Stanford Univ., Calif.
• NSA Number: NSA-17-003466
• OSTI ID: 4763997
• Report Number(s): ASD-TR-61-351; AD-275111
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CARBON
CARBON STEELS
DEFECTS
DEFORMATION
DIFFUSION
DISLOCATIONS
ELASTICITY
ELECTRIC ARCS
ELECTRON BEAMS
ETCHING
GRAIN SIZE
HEAT TREATMENTS
HYDROGEN
INTERSTITIALS
LATTICES
MEASURED VALUES
MELTING
METALS, CERAMICS, AND OTHER MATERIALS
NIOBIUM
NIOBIUM HYDRIDES
NITROGEN
QUANTITATIVE ANALYSIS
STEELS
STRESSES
TANTALUM
TEMPERATURE
THERMODYNAMICS