53nd Rolling Seminar — vol. 53, num.53 (2016)
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.
Intergranular oxidation, Selective oxidation, Thermogravimetry analysis, Cooling coils
Ronqueti, Larissa Agrizzi;
STUDY OF GRAIN BOUNDARY OXIDATION OF HIGH ALLOYED CARBON STEELS AT COILING TEMPERATURE
In: 53nd Rolling Seminar,
Rio de Janeiro,
ISSN: 2594-5297 , DOI 10.5151/1983-4764-27735