Award Date

12-2004

Degree Type

Thesis

Degree Name

Master of Science in Mechanical Engineering (MSME)

Department

Mechanical Engineering

First Committee Member

Ajit K. Roy, Chair

Second Committee Member

Anthony E. Hechanova

Third Committee Member

Brendan J. O’Toole

Graduate Faculty Representative

Jacimaria R. Batista

Number of Pages

80

Abstract

The susceptibility of Alloy EP-823 to stress corrosion cracking has been evaluated using smooth and notched cylindrical specimens in neutral and acidic solutions at ambient and elevated temperatures using constant load and slow strain rate testing (SSR) techniques. C-ring and U-bend specimens have also been tested in the acidic solution. The effect of hydrogen on the cracking susceptibility has been evaluated under controlled cathodic potential. While no failures were observed with smooth specimens at constant load, the notched specimens showed failure. The SSR test results indicate that the true failure stress (o'f), time to failure and ductility parameters were gradually reduced with increasing temperature irrespective of the solution pH. The presence of a notch, however, enhanced the magnitude of o'f. Neither C-ring nor U-bend specimens showed failure. Optical microscopy of the SSR specimen showed secondary cracking in the 90°C acidic solution. Fractographic evaluation by scanning electron microscopy revealed a combination of ductile (dimples) and brittle (intergranular/transgranular) failures.

Keywords

Harry Reid Center; Martensitic stainless steel – Cracking; Metals – Hydrogen embrittlement; Strains and stresses; Stress corrosion

Disciplines

Engineering Science and Materials | Materials Science and Engineering | Mechanical Engineering | Mechanics of Materials | Metallurgy | Nuclear Engineering

Language

English

Comments

Refer to PDF file for exact formulas.

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