Accession Number:

ADA067335

Title:

Research on Inhibition for Corrosion Fatigue of High Strength Alloys

Descriptive Note:

Final rept. 15 May 75-2 Oct 78

Corporate Author:

FLORIDA UNIV GAINESVILLE DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s):

• Verink, Ellis D., Jr.
• Das, K. Bhagwan

Report Date:

1978-12-15

Pagination or Media Count:

102.0

Abstract:

Over 200 potential inhibitor compositions were screened in selecting three final candidates to test in determining the effectiveness of oxidizing inhibitors in controlling hydrogen embrittlement of aerospace structural materials. Alloys tested included 4340, 300M, 17-4 PH, HP 9-4-30 and HY180. The three final inhibitors were the blocking type inhibitors, piperidine, and piperazine and a proprietary, polyfunctional inhibitor Nalco 39L. When present in sufficient concentration 1 M, the blocking inhibitors reduced hydrogen content at or near the fracture surface significantly, reduced the crack growth rate several orders of magnitude and increased K sub Iscc to approximately K sub Ic under static conditions. The polyfunctional inhibitor reduced measured hydrogen content to the lowest levels of the three inhibitors , however, only the manufacturers recommended concentration was generally effective. At lower as well as higher concentrations crack growth rates increased. At low concentrations, the fracture character resembled hydrogen embrittlement whereas at higher concentrations active path cracking was observed. Suggestions are made for future research. Author

Descriptors:

• *CORROSION INHIBITION
• *HIGH STRENGTH ALLOYS
• *STEEL
• POLARIZATION
• FRACTURE(MECHANICS)
• AEROSPACE SYSTEMS
• CRACK PROPAGATION
• HYDROGEN EMBRITTLEMENT
• STRESS CORROSION
• PIPERAZINES
• PIPERIDINES

Subject Categories:

• Properties of Metals and Alloys
• Fabrication Metallurgy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE