Evaluation of Hydroxyethane Diphosphonic Acid (HEDPA) as Metal Cleaning Agent Using Chemical and Electrochemical Test Methods: Part I

Abstract

In order to evaluate the adaptability of hydroxyethane diphosphonic acid (HEDPA) as an environmentally benign alternative rust removal agent, a systematic investigation is being carried out. The effectiveness of 2 vol.% (0.082 M) HEDPA was thoroughly investigated in the temperature range 27 - 60 deg C. The results suggest that the acid, HEDPA, is very effective in the rust removal process. It was found that the rust was completely removed by the HEDPA within 3 hours at 27 deg C, or within 30 minutes at 60 deg C. The rust dissolution process was found to have an activation energy of 11 +/- 1 kcal/mole. Prolonged treatment of samples with HEDPA results in the re-deposition of the reaction products onto the cleaned sample surface. The reaction product appears to be a mixture of complex higher order iron phosphates.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1998
Accession Number
ADA353280

Entities

People

  • A. S. Rao
  • John N. Murray

Organizations

  • Naval Surface Warfare Center Carderock Division

Tags

Communities of Interest

  • Advanced Electronics
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Adhesion
  • Body Weight
  • Chemical Analysis
  • Chemical Cleaning
  • Chemical Kinetics
  • Chemical Reactions
  • Chemical Synthesis
  • Chemistry
  • Energy
  • Heat Of Activation
  • Kinetics
  • Materials
  • Oxide Films
  • Oxides
  • Precipitation
  • Surface Warfare
  • Test Methods

Readers

  • Organic Chemistry
  • Positioning, Navigation, and Timing (PNT) Technology.
  • Surface Coatings Technology.