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


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a067335.pdf


Report Date : 15 Dec 1978


Pagination or Media Count : 102


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 manufacturer's 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