Effects of solution and intermediate heat treatments on the notch-rupture behavior of Inconel 718

Journal Article · Mon Dec 01 04:00:00 EST 1975 · Metall. Trans., A, v. 6A, no. 12, pp. 2221-2227

OSTI ID:4116800

Muller, J F; Donachie, Jr, M J

The effects of solution and intermediate heat treatments on the notch stress-rupture properties of Inconel 718 were investigated using commercial quality barstock. It was determined that a solution heat treatment of 1038$sup 0$C for as short a time as 20 min could render this alloy notch-sensitive by solutioning extensive quantities of the orthorhombic Ni$sub 3$Nb delta phase. Restoration of notch ductility subsequent to 1038$sup 0$C (20 min) solution heat treatment was accomplished by the insertion of a 917$sup 0$C (10 h) intermediate heat treatment, prior to aging, during which significant quantities of the delta phase were precipitated. This intermediate heat treatment was not successful in restoring notch ductility to specimens which had been given longer, 1 h, solution heat treatments at 1038$sup 0$C. A 954$sup 0$C (3 h) intermediate heat treatment was also not successful in restoring notch ductility to specimens solution heat treated for 20 min at 1038$sup 0$C. It was confirmed that the most important factors controlling the notch-rupture ductility in Inconel 718 are the size, quantity, and distribution of the delta phase. The grain size of the material did not directly control the notch properties. (auth)

• Research Organization: Los Alamos Scientific Lab., NM
• NSA Number: NSA-33-017734
• OSTI ID: 4116800
• Journal Information: Metall. Trans., A, v. 6A, no. 12, pp. 2221-2227, Journal Name: Metall. Trans., A, v. 6A, no. 12, pp. 2221-2227; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

*INCONEL 718-- FRACTURE PROPERTIES
360102* --Materials--Metals & Alloys--Structure & Phase Studies
AGING
DUCTILITY
HEAT TREATMENTS
N50230* --Metals
Ceramics
& Other Materials--Metals & Alloys--Properties
Structure & Phase Studies
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
RUPTURES
STRESSES
TIME DEPENDENCE
VERY HIGH TEMPERATURE