INFRARED SPECTROSCOPIC ANALYSIS OF PHASE TRANSFORMATION PROCESSES IN RUST LAYERS FORMED ON WEATHERING STEELS IN BRIDGE SPANS

Infrared spectroscopy (irs) was used to study the formation and transformation of rust phases and the weathering characteristics of ASTM a588 weathering steels in bridge spans. The technique enables not only clear differentiation between various rust phases, but also detects various forms of amorphous and not well-crystallized rust phases with clarity. Starting from the amorphous mix (am), a mixture of gamma-, delta-feooh, and ferrihydrite (f) in their highly amorphous forms, the rusting proceeds through the formation first of gamma-feooh or ferrihydrite, depending on atmospheric conditions, evolution of amorphous delta-feooh, which slowly crystallizes and final stabilization of delta-feooh containing traces of gamma-feooh. Gamma-fe2o3 h2o forms in the intermediate stages of transformation of gamma-feooh going over to delta-feooh. Alpha-feooh might emerge ultimately as the most stable phase. However, its formation is found to be very slow and heavily dependent on certain prevalent conditions, including very high or very low ph values of the condensate. Beta-feooh was not found even in coastal locations. Fe3o4 forms in sheet-type rusts at the rust-metal interface in chloride-rich condensates. (a)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00109312
• Authors:
  • Raman, A
  • Kuban, B
• Publication Date: 1988-7

Language

• English

Media Info

• Pagination: p. 483-8
• Serial:
  • CORROSION
  • Volume: 44
  • Issue Number: 7
  • Publisher: NACE International
  • ISSN: 0010-9312

Subject/Index Terms

• TRT Terms: Bridges; Electromagnetic spectrum; Hydration; Infrared radiation; pH value; Rusting; Steel; Weathering
• Uncontrolled Terms: Rust
• ITRD Terms: 3455: Bridge; 5252: Corrosion; 7195: Hydration; 6797: Infrared; 7116: pH value; 6776: Spectrum; 4542: Steel; 5281: Weathering
• Subject Areas: Bridges and other structures;

Filing Info

• Accession Number: 00482236
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Apr 30 1989 12:00AM