The grain-boundary segregation of phosphorus and carbon in Fe-P-C alloy during cooling
- BNFL, Berkeley (United Kingdom). Technology and Central Engineering Div.
- Univ. of Birmingham (United Kingdom). School of Metallurgy and Materials
Grain-boundary segregation in the Fe-P-C system has been examined using Auger Electron Spectroscopy on specimens which were cooled slowly to various intermediate temperatures after equilibration at 600 C, and then quenched prior to examination. The aim was to monitor the segregation of phosphorus and carbon through temperature ranges which offered the extremes of both solutes having long-range lattice mobility to that where only carbon was mobile. This approach revealed new complexities in the segregation process. It was found that phosphorus continued to segregate during the early stages of both furnace and air cooling, i.e. when long-range lattice diffusion remained possible. At intermediate temperatures, when the mobility of phosphorus was limited, an apparently competitive process occurred between the solutes, i.e. phosphorus de-segregated while the grain-boundary concentration of carbon increased. At temperatures less than approximately 200 C, carbon segregation continued under furnace cooling but not under air cooling but in neither case did phosphorus continue to de-segregate. A theoretical framework is developed which can account qualitatively for these segregation characteristics.
- OSTI ID:
- 302373
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 18 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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