论文部分内容阅读
Oxidation kinetics of two stainless steels was studied at 1000?1150°C from 0 to 600 s in humid air containing 18%water vapour by a Thermo Gravimetric Analysis(TGA).Incubation time decreases significantly with increasing temperature.Short time oxidation and tensile tests of the ferritic stainless steels SUS430 and B445J1M were carried out in the Gleeble 3500 thermo-mechanical simulator between 1000 and 1150 °C for 180 s in a humid atmosphere with 18%water vapour.Two strain rates 0.2 and 4 s?1 were used in the tensile tests.The results show that the temperature has significant effect on the thickness and compositions of the oxide scale during the short time oxidation.The tertiary scale failure pattern under tensile stress depends on the steel grades,temperature and strain rate.On the steel SUS 430,the compositions of the oxide scale begin to change from a thin chromia layer to multi-layers as the temperature is higher than 1150 oC in the short time oxidation.Two oxide scale failure modes occur on multi-layer oxide scale indicating that there is a weak interface between the iron oxides and Fe-Cr spinel and also the weak iron oxides.For B445J1M,the oxide scale formed at higher temperature exhibited less dense oxide scale cracks and a very thin oxide scale reappeared on the exposed steel substrate.This indicates that the sticking is more likely to occur at 1000 oC than that at or above 1050 oC.