Effect of Oxidation Temperature on the Oxidation Process of Silicon-Containing Steel

Abstract

Abstract:The oxidation behavior of silicon-containing steel was studied by applying segmented heating routes similar to the atmosphere and heating process in an industrial reheating furnace. The oxidation tests were carried out on a simultaneous thermal analyzer at heating temperatures of 1150˝C-1300˝C. The morphologies of Fe 2 SiO 4 were observed by SEM, and the penetration depths of the Fe 2 SiO 4 layer at different oxidation temperatures were determined by using the Image-Pro Plus 6.0 software. The results show that at heating temperatures ě1235˝C, the oxidation rate and total oxidation mass gain have no relation with the heating temperature; the mass gain versus time follows a linear law after about 1164˝C (lower than the eutectic temperature of fayalite). In addition, the oxidation rate first decreases slowly and then drops from 1190˝C to 1210˝C during the isothermal holding stage. With the increase in temperature, the oxidation rate and mass gain also increase gradually; the relationship between the mass gain and time is close to a parabolic law. Moreover, at a heating temperature of 1150˝C, the oxidation rate decreases rapidly during the isothermal holding stage, and the mass gain versus time follows a parabolic law.

The Effect of P on the Microstructure and Melting Temperature of Fe2SiO4 in Silicon-Containing Steels Investigated by In Situ Observation

“…Figure 2 shows the SEM images of the oxide scale in the two tested steels obtained with the backscattered electron (BSE) detector. As depicted in previous studies [15,16], the oxide scale mainly consists of three different layers, i.e., the upper layer Fe2O3, middle layer FeO + Fe3O4, and inner layer FeO/Fe2SiO4. The outer layers of Fe2O3 and FeO + Fe3O4 are brittle and easy to wipe off, but the inner layer of FeO/Fe2SiO4 strongly adheres to the metal matrix and is retained completely.…”

“…Figure 2 shows the SEM images of the oxide scale in the two tested steels obtained with the backscattered electron (BSE) detector. As depicted in previous studies [15,16], the oxide scale mainly consists of three different layers, i.e., the upper layer to obtain the areas of Fe 2 SiO 4 in unit widths, the total areas are divided by the width of the measured images [11]. The red area represents the distributions of solid Fe 2 SiO 4 and the measured area can represent the amount of Fe 2 SiO 4 .…”

The Morphologies of Different Types of Fe2SiO4–FeO in Si-Containing Steel

“…Previous studies have confirmed that the iron scale in this steel contains Fe 2 O 3 , Fe 3 O 4 , FeO, and Fe 2 SiO 4 [11,14,15]. The intimal scale consists of Fe 2 SiO 4 and FeO.…”

“…Mouayd et al [12] and Suarez et al [13] found that the amount and penetrative depth of Fe 2 SiO 4 -FeO increases with the Si content. In addition, He et al [14] reported that the morphology of Fe 2 SiO 4 4 -FeO and provides a theoretical reference toward preventing red scale defect in Si-containing steels.…”

“…Due to the close relationship between red scale and Fe 2 SiO 4 -FeO, some studies on Fe 2 SiO 4 -FeO in Si-containing steels have been carried out [11][12][13][14]. Yuan et al [11] reported that the net-like morphology of Fe 2 SiO 4 -FeO is not obvious when the Si content is low.…”