scholarly journals High-Temperature Oxidation Resistance of Alumina-Forming Austenitic Stainless Steels Optimized by Refractory Metal Alloying

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Shuqi Zhang ◽  
Dandan Dong ◽  
Qing Wang ◽  
Chuang Dong ◽  
Rui Yang
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
National Laboratory ◽  
Austenitic Stainless Steels ◽  
Alloying Elements ◽  
Temperature Oxidation ◽  
Oak Ridge ◽  
Al2o3 Particles

Alumina-forming austenitic stainless steels are known for their superior high-temperature oxidation resistance. Following our previous work that solved the matching of major alloying elements in their specific 16-atom cluster formula, we here focus on the 800 °C air-oxidation resistance of 0.08 wt. % C alloy series satisfying cluster formula [(Al0.89Si0.05NbxTa0.06−x)-(Fe11.7−yNiyMn0.3)]Cr3.0−z(Mo,W)z, x = 0.03 or 0.06, y = 3.0 or 3.2, z = 0.07 or 0.2, to explore the effect of minor alloying elements Mo, Nb, Ta and W. This cluster formula is established particularly based on alloys which were originally developed by Oak Ridge National Laboratory. All samples are graded as complete oxidation resistance level according to Chinese standard HB 5258-2000, as their oxidation rate and oxidation-peeling mass are generally below 0.1 g/m2 × h and 1.0 g/m2, respectively. In alloys without Ta and W, a Cr2O3-type oxide layer is formed on the surface and Al2O3 particles of sizes up to 4 μm are distributed beneath it. In contrast, in Ta/W-containing alloys, a continuous protective Al2O3 layer is formed beneath the outer Cr2O3 layer, which prevents internal oxidation and provides the lowest weight gain. Instead of internal Al2O3 particles, AlN is formed in Ta/W-containing alloys. The W-containing alloy possesses the thinnest internal nitride zone, indicating the good inhibition effect of W on nitrogen diffusion.

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 Resistance of Austenitic Stainless Steels with High Silicon

1981 ◽  
Vol 67 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Hisao FUJIKAWA ◽  
Junichiro MURAYAMA ◽  
Nobukatsu FUJINO ◽  
Taishi MOROISHI ◽  
Yuji SHOJI
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
Austenitic Stainless Steels ◽  
Temperature Oxidation ◽  
High Silicon

High Temperature Performance of Cast CF8C-Plus Austenitic Stainless Steel

2010 ◽  
Author(s):  
Philip J. Maziasz ◽  
Bruce A. Pint
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Gas Turbines ◽  
National Laboratory ◽  
Austenitic Stainless Steels ◽  
Medium Size ◽  
Temperature Oxidation ◽  
Oak Ridge

Covers and casings of small to medium size gas turbines, can be made from cast austenitic stainless steels, including grades such as CF8C, CF3M, or CF10M. Oak Ridge National Laboratory (ORNL) and Caterpillar have developed a new cast austenitic stainless steel, CF8C-Plus, that is a fully-austenitic stainless steel, based on additions of Mn and N to the standard Nb-stabilized CF8C steel grade. The Mn addition improves castability, as well as increasing the alloy solubility for N, and both Mn and N act synergistically to boost mechanical properties. CF8C-Plus steel has outstanding creep-resistance at 600°–900°C, which compares well with Ni-based superalloys like alloys X, 625, 617 and 230. CF8C-Plus also has very good fatigue and thermal fatigue resistance. It is used in the as-cast condition, with no additional heat-treatments. While commercial success for CF8C-Plus has been mainly for diesel exhaust components, this steel can also be considered for gas-turbine and microturbine casings. The purpose of this paper is to demonstrate some of the mechanical properties and update the long-term creep-rupture data, and to present new data on the high-temperature oxidation behavior of these materials, particularly in the presence of water vapor.

High Temperature Oxidation of Chromium-Nickel Steels★

CORROSION ◽  
1959 ◽  
Vol 15 (3) ◽  
pp. 57-62 ◽  
Author(s):  
D. CAPLAN ◽  
M. COHEN
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
Surface Preparation ◽  
Austenitic Stainless Steels ◽  
Chromium Steel ◽  
Temperature Oxidation ◽  
Thin Oxide Film ◽  
Scale Layer

Abstract The scaling of austenitic stainless steels Type 302, 309 and 330 has been investigated by weight gain vs time measurements in air at 1600 to 2000 F and subsequent examination of the scales. As had been found previously with chromium steel, the curves exhibit breaks indicating intermediate periods of rapid oxidation due to disruption of the protective scale layer. Accumulation of silica at the metal/scale interface is found to contribute to this disruption; voids are considered to have the same effect. A distinction is drawn between such breaks and the type which arises from the extraordinary protectiveness of an initial thin oxide film, which is markedly affected by surface preparation and prior treatment. 3.2.3

Developing New Cast Austenitic Stainless Steels With Improved High-Temperature Creep Resistance

2007 ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Michael J. Pollard
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Creep Strength ◽  
Stainless Steels ◽  
Creep Resistance ◽  
National Laboratory ◽  
Austenitic Stainless Steels ◽  
Alloy Development ◽  
Oak Ridge ◽  
Wide Range

Oak Ridge National Laboratory (ORNL) and Caterpillar have recently developed a new cast austenitic stainless steel, CF8C-Plus, for a wide range of high-temperature applications, including diesel exhaust components and turbine casings. The creep-rupture life of the new CF8C-Plus is over ten times greater than that of the standard cast CF8C stainless steel, and the creep-strength is about double. Another variant, CF8C-Plus Cu/W has been developed with even more creep strength at 750–850°C. The creep-strength of these new cast austenitic stainless steels is close to that of Ni-based superalloys like 617. CF8C-Plus steel was developed in about 1.5 years using an “engineered microstructure” alloy development approach, which produces creep resistance based on formation of stable nano-carbides (NbC) and prevention of deleterious intermetallics (sigma, Laves). CF8C-Plus steel won a 2003 R&D 100 Award, and to date, over 32,000 lb have been produced in various commercial component trials. The current commercialization status of the alloy is summarized.

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