High Temperature Cyclic Oxidation Research Articles

High-temperature oxidation resistance and wear properties of functionally graded CrHfNbTaTiN high-entropy nitride coating on Ti alloy

High-entropy nitrides have emerged as promising alternatives to traditional protective coatings due to their excellent comprehensive properties. However, there is still a long-standing technical challenge in the design and manufacture of hard and high-temperature stable high-entropy nitride coatings. This study utilized first-principles calculations to evaluate the thermodynamic stability between high-entropy nitrides and corresponding high-entropy metals, as well as titanium alloy substrates, confirming the rationality of the structural design of the functional gradient high-entropy ceramic coating. Subsequently, a double-glow plasma surface alloying technique were conducted to prepare a CrHfNbTaTiN functional gradient high-entropy ceramic coating on titanium alloy, followed by high-temperature cyclic oxidation experiments and high-temperature ball-on-disk wear tests. The research demonstrates that the gradient composition coating exhibits strong interfacial bonding, with an adhesion strength of around 40 N. It maintains excellent oxidation resistance in environments below 700 °C and displays good high-temperature wear resistance. This study contributes to providing insights and guidance for the further development of high-temperature, high-hardness, and wear-resistant materials.

Microstructure, high-temperature cyclic oxidation, and hot corrosion behaviors of Inconel 718 alloy produced by laser-induction hybrid cladding

The microstructure evolution, cyclic oxidation, and hot corrosion behavior of the unheated-treated (As-built) and solution + double aging (SDA)-treated Inconel 718 alloys fabricated through laser-induction hybrid cladding (LIHC) were investigated. It was found that the as-built Inconel 718 alloy exhibits a columnar dendritic with intergranular Laves phase. After SDA-treated, γ", γ′, δ and carbide phases precipitated, the Laves phase became fine and dispersed. After cyclic oxidation, the Cr2O3 scales were formed on both as-built and SDA-treated LIHC-produced Inconel 718 alloy, which could provide good cyclic oxidation resistance for the Inconel 718 alloy. However, the as-built and SDA-treated LIHC-produced Inconel 718 alloy suffered severe hot corrosion in 95 wt% Na2SO4 + 5 wt% NaCl mixed salt solution and many corrosion products were generated, including Cr2O3, NiCr2O4, NaNbO3, Na2CrO4, NiFe2O4, Fe3O4, and NiO. Nevertheless, the SDA-treated sample showed better cyclic oxidation and hot corrosion resistance than the as-built sample, owing to the more compact Cr2O3 scale.

Superior anti-oxidation layer induced by PVA-boehmite sol-gel film on AISI304 steel

The superior anti-oxidation layer induced by the PVA-boehmite sol-gel film on the AISI304 steel during the cyclic oxidation is investigated in this work. The moderate PVA addition in the boehmite sol conduces to increase the film thickness and is beneficial to the adhesion between the film and the substrate. The presence of the PVA-boehmite film leads to a significant reduction in mass gain during the high-temperature cyclic oxidation at 800 °C, demonstrating the enhanced oxidation resistance. The generated oxide layer induced by the PVA-boehmite film presents as a thin, compact, and continuous layer without spalling, offering sustainable protection against oxidation etching. The PVA-boehmite film promotes the preferential formation of the corundum (Al, Cr)2O3 phase rather than the detrimental hematite Fe2O3 phase during the oxidation procedure, which facilitates the development of the above compact oxide layer. Finally, the superior anti-oxidation oxide layer is characterized as a novel dual-layer structure: the outer spinel MnCr2O4 layer and the inner corundum (Al, Cr)2O3 layer, effectively delaying the oxidation process.

Numerical simulation of high-temperature erosion of heat-resistant steel considering surface scale evolution

A study was conducted on heat-treated, heat-resistant steel S51740 to understand the issues surrounding gas turbine compressors. The study included high-temperature cyclic oxidation and high-temperature erosion tests at 400 °C, 600 °C, and 800 °C. We used the oxidation test data to establish dynamic erosion models using Ansys LS-DYNA software. We focused on the target's surface morphology, stress-strain, transient temperature, and failure characteristics during high-temperature erosion after high-temperature oxidation to reveal the erosion mechanism of oxidized steel. During cyclic oxidation, the specimen's microstructure was refined at 400 °C, with a 10 μm oxidation-affected zone emerging. At 600 °C, austenite appeared, forming a 20 μm oxidation-affected zone. Performance declined at 800 °C due to decarburization and segregation, resulting in a 50 μm oxidation-affected zone. High-temperature erosion on the oxidized specimens featured cutting and a chip-like morphology at 400 °C and 600 °C. At 800 °C, the specimen experienced a notable increase in mass loss and extensive plastic deformation on the surface. Erosion simulations revealed that rising temperatures increase the target's stress distribution, strain, and temperature zones. Reduced material strength leads to lower resistance to impact particles, converting high-speed kinetic energy to internal energy during erosion. Temperature spikes in impacted zones accelerate wear and adversely affect local mechanical properties. Lower ambient temperatures exacerbate the temperature increase from erosion, significantly influencing material erosion and wear resistance.

High-Temperature Cyclic Oxidation Behavior and Microstructure Evolution of W- and Ce-Containing 18Cr-Mo Type Ferritic Stainless Steel.

Due to the recurrent starting and stopping operations of automobiles during service, their engines' hot ends are continually subjected to high-temperature cyclic oxidation. Therefore, it is crucial to develop ferritic stainless steels with better high-temperature oxidation resistance. This study focuses on improving the high-temperature cyclic oxidation performance of 18Cr-Mo (444-type) ferritic stainless steel by alloying with high-melting-point metal W and the rare earth element Ce. For this purpose, a high-temperature cyclic oxidation experiment was designed to simulate the actual service environment and investigate the high-temperature cyclic oxidation behavior and microstructure evolution of 444-type ferritic stainless steel alloyed with W and Ce. The oxide structure and composition formed during this process were analyzed and characterized using scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS) and electron probe X-ray micro-analyzer (EPMA), in order to reveal the mechanism of action of W and Ce in the cyclic oxidation process. The results show that 18Cr-Mo ferritic stainless steel alloyed with W and Ce exhibits an excellent resistance to high-temperature cyclic oxidation. The element W can promote the precipitation of the Laves phase between the matrix and the oxide film, and the small-sized Laves phase can inhibit the interfacial diffusion of oxidation reaction elements and prevent the inward growth of the oxide film. The element Ce can refine oxide particles and reduce the thickness of the oxide film. CeO2 particles within the oxide film can serve as nucleation sites for the formation of oxide particles from reactive elements, and they also contribute to pinning the oxide film, thereby enhancing its adhesion.

High-temperature cyclic oxidation of micro- and nano-ZrO2–25wt.%CeO2–2.5wt.%Y2O3 thermal barrier coatings at 1300 °C

In this study, the high-temperature cyclic oxidation resistance of micro- and nano-ZrO2–25wt.%CeO2–2.5wt.%Y2O3 (CYSZ) thermal barrier coatings (TBCs) was investigated. The TBCs were applied on IN738LC/CoNiCrAlY using the atmospheric plasma spray (APS) technique and subjected to high-temperature cyclic oxidation through 5-h cycles at 1300 °C. Various characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, nanoindentation, and field-emission scanning electron microscopy (FESEM), were used to assess the TBCs. Results indicated that annealing tetragonal zirconia at 1300 °C can generate antiphase boundary defects. The Young's modulus and hardness of nano- and micro-CYSZ TBCs decrease with the increase of antiphase boundary density. XRD and Raman results, the phase transformation behavior of tetragonal zirconia can be correlated to antiphase boundary density. Furthermore, the study showed that the nano-CSZ TBC has better oxidation resistance than the micro-CYSZ TBC at 1300 °C.

Development, Characterization and High-Temperature Oxidation Behaviour of Hot-Isostatic-Treated Cold-Sprayed Thick Titanium Deposits

In this work, thick deposits of pure titanium (Ti), with a thickness of around 15 mm, were additively manufactured using high-pressure cold spraying. Nitrogen was employed as the process gas. Subsequently, the deposits were subjected to hot isostatic pressing (HIP). The HIP-treated Ti deposits were analyzed for their metallurgical and mechanical characteristics with the aim of exploring the viability of using cold spraying for the additive manufacturing of Ti components. Moreover, high-temperature cyclic oxidation testing was also performed on the HIP-treated Ti deposit to understand its stability at high temperatures. SEM/EDS showed a dense structure with marginal porosity for the HIP-treated Ti deposits, without any oxide formation, which was further confirmed via XRD analysis. An average microhardness of 214 HV was measured for the HIP-treated Ti deposits, which is close to that of the commercially available bulk titanium (202 HV). The high-temperature oxidation studies revealed that the cold-sprayed HIP-treated Ti has very good oxidation resistance, which could be attributed to the formation of protective titanium dioxide in its oxide scale.

Effects of thermal and mechanical properties of Hf and Ta-doped NiCoCrAlY bonding layer alloys on the high-temperature oxidation resistance of thermal barrier coatings

The MCrAlY bonding layer alloy was prepared by vacuum melting, and the alloy composition was NiCoCrAlY and NiCoCrAlYHfTa. The high-temperature cyclic oxidation experiment was carried out in air at 1050∘C until it failed. The results show that Hf and Ta have a significant influence on the oxidation resistance of the alloy. The doped specimens have longer oxidation lifetimes compared to the undoped samples. The study also found that the Hf would diffuse out and combine with O to form HfO2 in the thermally grown oxide (TGO) layer, which would improve the adhesion and reduce the wrinkles of the oxide layer. Ta in the doped specimens hinders the diffusion of Al and reduces the oxidation rate, while improving the thermal mismatch. Therefore, the specimens doped with both Hf and Ta have the highest oxidation lifetimes, though the oxidation lifetime was 10 times longer than that of the undoped specimens. It is indicated that the doping of Hf and Ta is an important method to improve the oxidation lifetime of thermal barrier coatings (TBCs).

Microstructure and oxidation resistance of Al50(Fe–Cr)(50-x)(SiC)x composite coated low-carbon steel prepared by mechanical milling

In this study, the influence of silicon carbide (SiC) content on microstructure and oxidation behavior of the Al50(Fe–Cr)(50-x)(SiC)x composite coating on low-carbon steel was studied for the first time. The correlation between the microstructure and oxidation behavior of the Al50(Fe–Cr)(50-x)(SiC)x composite coating at different SiC content was determined using X-ray diffraction (XRD), optical microscope, and scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The result confirms that the phase and microstructure of the coating is a composite structure consisting of highly densified and porous regions. The addition of SiC (5 at.%) on the composite coating improves the microstructure quality, but increasing SiC more than 5 at.% causes the increment of micro-porosity. The high-temperature cyclic oxidation results at 800 °C for 200 h revealed that all composite coating followed a parabolic rate law. The best oxidation resistance is shown by the addition of 5 at.% SiC on the Al50(Fe–Cr)(50-x)(SiC)x composite coating. It indicated a lower Kp of 0.84 × 10−3 mg2/cm4.s than the other samples. Moreover, the protective oxides of Al2O3 were formed on the composite coating surface. This oxide scale is dense and fully adhered to the coating, thus improving oxidation resistance.

Cyclic High-Temperature Oxidation Behavior of Bare and Nicr Coated Aisi 422 Steam Turbine Blade Steel

Cyclic High-Temperature Oxidation Behavior of Bare and Nicr Coated Aisi 422 Steam Turbine Blade Steel

High temperature oxidation behavior of thermal and plasma processed aluminide coated Ti6Al4V alloys

In this study, the high temperature cyclic oxidation behavior of thermal and plasma-treated aluminide coated Ti6Al4V alloy was investigated at 800 °C up to 360 h in 24 h cyclic exposures. The microstructural characteristics, phase analysis, morphological features, and microhardness of resultant oxidized samples were evaluated and compared with those of untreated Ti6Al4V alloy. The weight gain studies conducted from the cyclic oxidation tests revealed very minimal weight gain in plasma treated (PT) aluminide coated samples as compared to the thermal treated (TT) and uncoated (UC) samples. XRD results indicate that the UC samples oxidized at 800 °C exhibits the formation of a thick oxide layer consisting of only the rutile phase (TiO2). The TT and PT samples oxidized at 800 °C revealed presence of both alumina (Al2O3) and rutile (TiO2) phases. However, PT samples revealed stable α-Al2O3 phase whereas the TT samples showed metastable θ-Al2O3 phases in the oxide layer. The surface morphological features reveal that the oxide film formed on the surface of the PT samples had enough stability at 800 °C irrespective of the oxidation time. The PT samples exhibited higher hardness and improved oxidation resistance as compared to TT and UC samples. Increase in thermal stability, mechanical and oxidation properties of PT samples could be attributed to the formation of stable alumina (α-Al2O3) and presence of nanocrystalline aluminide phases (TiAl3 & TiAl2) in the diffusion layers during the oxidation tests. Therefore, a strong emphasis was placed on correlating the interfacial processes to the high temperature oxidation behavior.

Oxidation Kinetic and Oxide Scale Morphology of Fe-33Ni-19Cr Ni-Based Superalloy

In the present study, outcome of various grain size of heat treated Fe-33Ni-19Cr Ni-based superalloy at high temperature cyclic oxidation condition was investigated. The Fe-33Ni-19Cr Ni-based superalloy was experienced a series of heat treatment process at two assorted temperatures, which are 1000 °C and 1100 °C, soaking for 3 hours and then rapid cooled by water quench. The heat treatment process produced a fine and coarse grain size structure. The cyclic oxidation test was performed for both heat treated samples at 700 °C under cyclic conditions in the laboratory air for 150 cycles. The weight change was measured discontinuously at different cycles to identify the kinetics of oxidation. SEM and FESEM outfitted with EDX spectrometer were utilized to analyzed the oxidation product. As a result, the weight change increased with time, with fine grain HT1000 sample recorded lower weight gain compared to coarse grain HT1100 sample. In addition, both sample formed uniform and continuous oxide scale on the alloy surface.

High temperature oxidation resistance of an amorphous layer induced by ion implantation on the surface of Ni-based superalloy GH202

The high-temperature cyclic oxidation behavior of Ni-based superalloy GH202 was investigated before and after Y ion implantation at 1100 °C. The chemical composition and microstructure of the alloy surface treated by ion implantation were characterized using X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, electron probe microanalysis, and scanning electron microscopy. The results showed that a 30-nm-thick amorphous layer formed on the surface of the superalloy. The collision of Y ions with the alloy atoms resulted in a large number of crystal defects, such as vacancies and dislocations. Upon increasing the implantation dose, the shock of the ions prompted the dislocations to move and form dislocation tangles and dislocation arrays, which provided short circuit diffusion channels for aluminum (Al) ions during high-temperature oxidation. The oxide film on the surface of the specimens treated by ion implantation remained intact after 40 oxidation cycles, and no internal oxidation occurred in the substrate. The Y ions provided heterogeneous nucleation particles, reduced the distance between the Al2O3 nucleation positions, and promoted the formation of continuous, dense films. The amorphous layer changed the oxidation mechanism from outward cation diffusion in the oxide films to inward anion diffusion. The growth rate of the oxide film was effectively inhabited, and the high-temperature oxidation resistance was significantly improved.

Analysis of plasma gun sprayed coatings on SS-304 steel to evaluate cyclic oxidation and hot corrosion

Power plants, gas power turbines and chemical based plants face a very big issue of accelerated type of corrosion i.e hot corrosion, because of which the lifespan of metal decreased to large extent. In the present investigation, S-304 steel was taken which is commonly used in thermal power plants for inspection of accelerated corrosion i.e hot corrosion and high temp. oxidation behaviour. Alumina plus 13% titanium(Al2O3 + 13%TiO2), Alumina plus 3% titanium (Al2O3 + 3%TiO2) , Alumina(Al2O3)powder was applied on the boiler steel samples by using plasma spraying process. The uncoated and coated samples were exposed for 50 cycles to cyclic high temperature oxidation in air at 900 °C and hot corrosion in molten salt conditions of sodium sulphate and vanadium oxide (Na2SO4 – 60% V2O5) at 900 °C. In Oxidation study, with weight gain of 1.86% the upmost resistance against oxidation was exhibited by Alumina plus 13% titanium coated(Al2O3 + 13%TiO2) followed by Alumina plus 3% titanium coated (Al2O3 + 3%TiO2) with weight gain of 2.36% and by 2.92% by Alumina coated(Al2O3). The least resistance was shown by bare S-304 with weight gain of 3.91%.In investigation of hot corrosion, the weight gain percentages of Alumina plus 13% titanium coated(Al2O3 + 13%TiO2) is 2.46%, Alumina plus 3% titanium coated (Al2O3 + 3%TiO2) coated is 2.92%, Alumina coated(Al2O3) is 3.77% and for uncoated its 4.67%. The outcomes obtained for protection against oxidation and hot corrosion is: plus 13% titanium (Al2O3 + 13%TiO2) > Alumina plus 3% titanium (Al2O3 + 3%TiO2) coated > Alumina(Al2O3) > uncoated S-304 boiler steel.

The effect of alloying elements on oxide scale spallation of multicomponent Co-based superalloys

The characterization of high temperature cyclic oxidation behavior of as-cast and as-aged Co-(Ni)-Al-W alloys, and the influence of alloying elements on oxide spallation resistance have been investigated in this study. The cyclic oxidation and oxide scale morphology of the alloys are analyzed from 700° to 900°C. It has been observed that the ternary Co-Al-W alloys are prone of oxide scale spallation and increasing the Al, W and Ni contents improves the cyclic oxidation resistance of the alloys. The structural effect of Ni on oxidation performance is related to its introduction to single and complex oxides present in a scale.

Data analytics approach to predict high-temperature cyclic oxidation kinetics of NiCr-based Alloys

Although of practical importance, there is no established modeling framework to accurately predict high-temperature cyclic oxidation kinetics of multi-component alloys due to the inherent complexity. We present a data analytics approach to predict the oxidation rate constant of NiCr-based alloys as a function of composition and temperature with a highly consistent and well-curated experimental dataset. Two characteristic oxidation models, i.e., a simple parabolic law and a statistical cyclic oxidation model, have been chosen to numerically represent the high-temperature oxidation kinetics of commercial and model NiCr-based alloys. We have successfully trained machine learning (ML) models using highly ranked key input features identified by correlation analysis to accurately predict experimental parabolic rate constants (kp). This study demonstrates the potential of ML approaches to predict oxidation kinetics of alloys over wide composition and temperature ranges. This approach can also serve as a basis for introducing more physically meaningful ML input features to predict the comprehensive cyclic oxidation behavior of multi-component high-temperature alloys with proper constraints based on the known underlying mechanisms.

Effects of silicon and manganese content on the oxidation behavior of FeMnSiCrNi alloys and the correlation between Mn-depleted zone, surface roughness and oxidation resistance

Manganese and silicon effect on high-temperature cyclic oxidation was evaluated in three austenitic shape-memory FeMnSiCrNi alloys, including a novel high-silicon alloy (Fe-17Mn-8Si-10Cr-4Ni-NbC). Mass variation, Mn-depleted zone and metal/oxide interface roughness analyses were used to study the oxidation behavior. Renewed mass gain after spallation was observed for Fe12Mn5Si and Fe17Mn5Si alloys, while Fe17Mn8Si continuously lost mass, associated with low metal/oxide interface roughness and the ferritizing potential of Si. Low manganese availability led Fe12Mn5Si to suffer internal oxidation and iron oxide formation. Here, neither increasing silicon nor reducing manganese increased cyclic oxidation resistance of the alloys.

High-temperature cyclic oxidation behavior and mechanism of Mo2FeB2-based cermets with various boron contents

In this study, cyclic oxidation behavior and mechanism of Mo2FeB2-based cermets have been investigated by varying the boron content. The parabolic curves of mass gain confirmed the formation of the protective oxide layer. Mo2FeB2-based cermets with boron content of 6 wt.% had the lowest mass gain due to the denser and continuous oxide layer. A typical multi-layer structure could be observed in the cross-section, which was mainly composed of Fe oxide, borate and molybdate. The borate layer could effectively inhibit the diffusion of oxygen to protect the matrix from rapid oxidation. Furthermore, higher boron content could facilitate the oxide layer to be denser, which is beneficial to the oxidation resistance. However, the “pesting oxidation” would appear after 50 h oxidation at 800 °C, which causes the curves of mass gain to transform from parabolic to linear trend.

Microstructural and high-temperature cyclic oxidation response of NiCoCrAlY coatings with and without SiC + ZrB2 reactive-element dispenser

In this study, the microstructural and cyclic-oxidation evolution behavior of bond coats (BC) containing SiC + ZrB2 dispersed particles were evaluated. The SiC + ZrB2 dispersed particles at the oxidation temperature of 1130 °C, dissolved at early stages, stabilizing the beta phase, diminishing the aluminum outward diffusion. The silicon at the BC/TC interface, or very close to it, behaved as a reactive element promoting the rapid formation and stabilization of α-Al2O3 (TGO), and a second scale layer of mixed oxides and silicon-rich compounds, jointly limiting inward oxygen diffusion and resulting in thinner TGO layers, whose kinetic oxidation follows a sub-parabolic behavior, increasing oxidation life-span.

High temperature cyclic oxidation behavior of a low manganese Fe12Mn9Cr5Si4Ni-NbC shape memory stainless steels

High amounts of Mn in Fe-Mn-Si-Cr-Ni shape memory stainless steels are detrimental for oxidation resistance at high temperatures. However, in order to maintain the shape memory effect of these alloys the content of manganese must be between 12 and 19 wt%. Thus, this study evaluated an alloy with relative low Mn (12 wt%) in cyclic oxidation tests at 800, 900 and 1000 °C. Kinetic analysis demonstrated parabolic oxidation behavior with rate similar to higher Mn-containing alloys from literature. It was also observed internal oxidation, for the first time in these alloys, and oxide layers composed by Mn2O3 and Mn-Cr spinel at 800 °C as well as Mn-Cr spinel and no continuous silica at 1000 °C. The internal oxidation mechanism was related to oxide layer defects and not to partial oxygen pressure decrease, considering that the internal oxidation presented the same oxides of the external layer. These results show that low Mn content does not improve the use viability of these alloys at high temperatures, since no decreasing in oxidation rate was observed and further internal oxidation occurred.