Título

STUDY OF GRAIN BOUNDARY OXIDATION OF HIGH ALLOYED CARBON STEELS AT COILING TEMPERATURE

Autoria

Ronqueti, Larissa Agrizzi; Favergeon, Jérôme; Risbet, Marion; Picard, Michel

DOI

10.5151/1983-4764-27735

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Resumo

The effect of coiling temperature on selective oxidation behaviour of binary and ternary iron-based model alloys containing different contents of Si or Mn were investigated by SEM and SIMS. The experiments were carried out with a temperature ranging from 450 °C to 700 °C, under N2-5%H2 gas flow with a Dew Point of -3.3°C, for different durations. SEM images of binary iron-based model alloys revealed a decrease of grain boundary oxidation depth with increasing Silicon or Manganese content. At 530°C and 600°C SIMS results showed no Silicon diffusion toward surface, contrary to the results analyzed for Fe-x%Mn. Tests results and Wagner’s theory application (specific cases Fe-0.2%Si and Fe-0.5%Si) showed that grain boundary oxygen diffusion coefficient “DoGB” is almost 60 to 70 times faster than oxygen bulk diffusion coefficient. These results helped to broaden knowledge of single-element effects on grain boundary oxidation, in addition, will contribute of the future works in new steels with complex alloy compositions.

 

Palavras-chave

Intergranular oxidation, Selective oxidation, Thermogravimetry analysis, Cooling coils

Cooling coils