Effect of heat treatment on SCC and HEC of precipitate-hardenable alloy in sour gas environment

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6674482

Takaoka, T; Ishizawa, Y; Misao, H; Yamada, T ^[1]

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1. NKK Corp., 1-1 Minamiwatarida-cho, Kawasaki 210 (JP)

This paper reports on a gamma prime precipitate hardenable alloy (22%Cr-48%Ni-3%Mo-2.7%Ti-0.6%Al-0.5%Nb-Fe) tested for the resistance to SCC (stress corrosion cracking) and HEC (hydrogen embrittlement cracking) in H{sub 2}S and Cl environments. In this alloy, the susceptibility to both SCC and HEC was enhanced by the increase of the yield strength rather than by aging conditions. In addition to gamma prime precipitation in matrix, M{sub 23}C{sub 6} carbide and sigma phase precipitated at grain boundaries during high temperature aging with time. This sigma phase was not only deleterious for ductility, but also enhanced the intergranular SCC. The grain size also affected the susceptibility to the cracking. Further, it was considered that the evaluation of SCC resistance by the SSRT method was more severe than that by the constant strain method for this type of precipitate hardenable alloys.

• OSTI ID: 6674482
• Report Number(s): CONF-890437--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
022000* -- Petroleum-- Transport
Handling
& Storage
36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
AGE HARDENING
ALLOYS
CHEMICAL REACTIONS
CORROSION
CORROSIVE EFFECTS
CRYSTAL STRUCTURE
EMBRITTLEMENT
ENVIRONMENT
GEOLOGIC DEPOSITS
GRAIN BOUNDARIES
HARDENING
HEAT TREATMENTS
HYDROGEN EMBRITTLEMENT
IMPACT STRENGTH
INTERGRANULAR CORROSION
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
MINERAL RESOURCES
NICKEL ALLOYS
NICKEL BASE ALLOYS
OIL FIELDS
PETROLEUM DEPOSITS
RESOURCES
STRESS CORROSION
TESTING