Effect of Grain Size on the High Temperature Oxidation Behaviour of Austenitic Stainless Steels

2013 ◽  
Vol 333 ◽  
pp. 149-155 ◽  
Author(s):  
H. Fujikawa ◽  
Y. Iijima
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Mass Gain ◽  
Oxidation Behaviour ◽  
Solution Temperature ◽  
Oxide Interface ◽  
Temperature Oxidation ◽  
Coarse Grains

The effect of grain size on high temperature oxidation behaviour of 316 steels at 700º, 850º and 1000°C in air was studied. The results show that the mass gain increases with the increase of grain size. Particularly, the gradient of mass gain is severe in at lower oxidation temperatures. In the oxidation at temperatures of more than the solid solution temperature, the grain size before the oxidation changed to coarse grain size. Therefore, in this case, it is not enough to estimate the oxidation behaviour by the grain size before the oxidation. The exfoliation of oxide scale is severe in steel with coarse grains. Over 850°C, the exfoliation was observed in 316 steel with coarse grains. At 1000°C, the oxide scale of 316 steel was exfoliated, but it was extreme in the coarse grains. Cr, Mn and Si in the oxide scale were enriched in the oxide scale of the steel with fine grains. Particularly, Si was remarkably enriched at the metal-oxide interface and grain boundaries.

Review of Several Studies on High Temperature Oxidation Behaviour and Mechanism of Austenitic Stainless Steels

2011 ◽  
Vol 312-315 ◽  
pp. 1097-1105
Author(s):  
Hisao Fujikawa
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
Austenitic Stainless Steels ◽  
Oxidation Behaviour ◽  
Oxide Interface ◽  
Temperature Oxidation

Three studies on the oxidation behaviour of austenitic stainless steels were described in the present paper. (1) High temperature oxidation behaviour and its mechanism in austenitic stainless steels with high silicon: Sulfur contained as impurity in steel showed a harmful influence to the oxidation resistance of 19Cr-13Ni-3.5Si stainless steels. It was found that the abnormal oxidation was caused from the surroundings of MnS inclusions. (2) Effect of a small addition of yttrium on high temperature oxidation resistance of Si-containing austenitic stain less steels: The oxidation resistance of 19Cr-10Ni-1.5Si steels was improved remarkably even with only 0.01%Y addition, which is the same concentration as added for de-oxygenation. Y was enriched at the grain boundary of oxide scale and metal-oxide interface. It was suggested that Y-containing steels shoed good oxidation resistance, because the enriched Y at the grain boundary and metal-oxide interface prevented the diffusion of iron and oxygen ions through the oxide scale. (3) Effect of grain size on the oxidation behaviour of austenitic stainless steels: Type 304, 316 and 310 steels with finer grain size showed better oxidation resistance than those with coarser grain size at 850°C. The oxide scale of steels with coarser grain size easily spalled during the cooling process.

scholarly journals High Temperature Oxidation Behavior of Selective Laser Melting Manufactured IN 625

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 668 ◽  
Author(s):  
Mihaela Raluca Condruz ◽  
Gheorghe Matache ◽  
Alexandru Paraschiv ◽  
Teodor Badea ◽  
Viorel Badilita
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
Selective Laser Melting ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Complex Oxide ◽  
Mass Gain ◽  
Laser Melting ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

The high-temperature oxidation behavior of selective laser melting (SLM) manufactured IN 625 was studied over 96 h of exposure at 900 °C and 1050 °C in air. An extensive analysis was performed to characterize the oxide scale formed and its evolution during the 96 h, including mass gain analysis, EDS, XRD, and morphological analysis of the oxide scale. The mass gain rate of the bare material increases rapidly during the first 8 h of temperature holding and diminishes at higher holding periods for both oxidation temperatures. High-temperature exposure for short periods (24 h) follows a parabolic law and promotes the precipitation of δ phase, Ni-rich intermetallics, and carbides. Within the first 24 h of exposure at 900 °C, a Cr2O3 and a (Ni, Fe)Cr2O4 spinel scale were formed, while at a higher temperature, a more complex oxide was registered, consisting of (Ni, Fe)Cr2O4, Cr2O3, and rutile-type oxides. Prolonged exposure of IN 625 at 900 °C induces the preservation of the Cr2O3 scale and the dissolution of carbides. Other phases and intermetallics, such as γ, δ phases, and MoNi4 are still present. The exposure for 96 h at 1050 °C led to the dissolution of all intermetallics, while the same complex oxide scale was formed.

High-Temperature Oxidation Behavior of Cu-Si-Y Alloys

2013 ◽  
Vol 32 (4) ◽  
pp. 397-403
Author(s):  
Qun Liu ◽  
Guangyan Fu ◽  
Yong Su ◽  
Zhigang Zhang ◽  
Qi Xiong
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Mass Gain ◽  
Alloying Elements ◽  
Experimental Conditions ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

AbstractThe effect of rare-earth element Y on high-temperature oxidation behavior of Cu-Si alloys at 973 and 1073 K in 0.1 MPa flowing pure O2 has been investigated. Results show at the two temperatures the mass gain of the alloys with different compositions follows the following sequence, Cu-3Si-1.0Y > Cu-3Si-0Y > Cu-3Si-0.5Y alloy. As the Y content increases, the grain size of the alloys decreases, which accelerates the diffusion rate of the alloying elements in the alloys and oxygen under the experimental conditions, increases the ratio of short-path diffusion, and promotes the formation of SiO2 and Y2O3. The three alloys do not form continuous oxide scales of SiO2 or Y2O3, but their rapid formation and dispersed distribution due to the grain-size reduction may also hinder the diffusion of alloying elements and oxygen, which is beneficial to improve the oxidation resistance of the Y-containing alloys. Thereby, the Cu-3Si-0.5Y alloy has good oxidation resistance. The Cu-3Si-1.0Y alloy exhibits largest mass gain among the three alloys, which is due to the fact that in the alloy with higher Y contend and finer grain size, more amount of Y2O3 is more quickly formed, whose mass occupy a more proportion in the whole mass gain of the alloy.

scholarly journals Friction and Wear of Oxide Scale Obtained on Pure Titanium after High-Temperature Oxidation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3764
Author(s):  
Krzysztof Aniołek ◽  
Adrian Barylski ◽  
Marian Kupka
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Friction And Wear ◽  
High Carbon Steel ◽  
Oxide Films ◽  
Oxidation Temperature ◽  
Temperature Oxidation ◽  
Wear Ratio ◽  
Steel Balls

High-temperature oxidation was performed at temperatures from 600 to 750 °C over a period of 24 h and 72 h. It was shown in the study that the oxide scale became more homogeneous and covered the entire surface as the oxidation temperature increased. After oxidation over a period of 24 h, the hardness of the produced layers increased as the oxidation temperature increased (from 892.4 to 1146.6 kgf/mm2). During oxidation in a longer time variant (72 h), layers with a higher hardness were obtained (1260 kgf/mm2). Studies on friction and wear characteristics of titanium were conducted using couples with ceramic balls (Al2O3, ZrO2) and with high-carbon steel (100Cr6) balls. The oxide films produced at a temperature range of 600–750 °C led to a reduction of the wear ratio value, with the lowest one obtained in tests with the 100Cr6 steel balls. Frictional contact of Al2O3 balls with an oxidized titanium disc resulted in a reduction of the wear ratio, but only for the oxide scales produced at 600 °C (24 h, 72 h) and 650 °C (24 h). For the ZrO2 balls, an increase in the wear ratio was observed, especially when interacting with the oxide films obtained after high-temperature oxidation at 650 °C or higher temperatures. The increase in wear intensity after titanium oxidation was also observed for the 100Cr6 steel balls.

High-Temperature Oxidation of Stellite 12 Hardfacings: Effect of Mo on Characteristics of Oxide Scale

2018 ◽  
Vol 28 (1) ◽  
pp. 463-474 ◽  
Author(s):  
Amir Motallebzadeh ◽  
Shaikh Asad Ali Dilawary ◽  
Erdem Atar ◽  
Huseyin Cimenoglu
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
Stellite 12
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