Hydrogen-enhanced transient creep of 310S and AL 29-4-2 stainless steel

Transient creep of hydrogenated 310S and AL 29-4-2 stainless steels at ambient temperatures was studied to determine the effects of hydrogen on plastic deformation. Thin specimens were slowly cathodically charged to uniform hydrogen contents, and no significant damage was introduced. A constant load was then applied while the charging current density remained the same, so as to prevent outgassing of the hydrogen during creep tests. It was found in 310S that at short times the creep rate of a hydrogenated specimen was lower than for a specimen without hydrogen. However, the creep rate decreased at a slower rate thereafter, so that the transient creep stage was longer, and in some cases, the creep strain was even larger than in a hydrogen-free specimen. In AL 29-4-2, the hydrogenated specimen had a higher creep rate than the uncharged specimen from beginning to the end of the creep test. This is clear evidence of hydrogen-enhanced plasticity. Elastic interactions between hydrogen atmospheres and moving dislocations were used to explain the observed phenomenon. Hydrogen-enhancement and localization of plasticity have been cited as fundamental causes of hydrogen embrittlement. The prolongation of the transient creep stage has significance for propagation of stress corrosion cracks.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Tien, Chee Wain

Contributors dc:contributor

• Altstetter, Carl J.

• Engineering, Metallurgy
• Engineering, Materials Science

Statement dc:rights

• Copyright 1994 Tien, Chee Wain

Language dc:language

eng

Identifier

AAI9503337
(UMI)AAI9503337

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20408