Yttrium Implantation and Manganese Addition Element Effects on the High Temperature Oxidation Resistance of a Model Steel

2008 ◽  
Vol 595-598 ◽  
pp. 897-905
Author(s):  
Eric Caudron ◽  
Régis Cueff ◽  
Christophe Issartel ◽  
N. Karimi ◽  
Frédéric Riffard ◽  
...  

Manganese addition and subsequent yttrium implantation effects on extra low carbon steel were studied by Rutherford Backscattering Spectrometry (RBS), Reflection High Energy Electron Diffraction (RHEED), X-ray Diffraction (XRD) and Glancing Angle X-ray Diffraction (GAXRD). Thermogravimetry and in situ X-Ray Diffraction at 700°C and PO2=0.04 Pa for 24h were used to determine the manganese alloying addition and subsequent yttrium implantation effects on reference steel oxidation resistance at high temperatures. This study clearly shows the combined effect of manganese alloying addition and subsequent yttrium implantation which promotes the formation of several yttrium mixed oxides seem to be responsible for the improved reference steel oxidation resistance at high temperatures.

2015 ◽  
Vol 817 ◽  
pp. 421-425
Author(s):  
Kun Zhao ◽  
Wan Chang Sun ◽  
Chun Yu Miao ◽  
Hui Cai ◽  
Ju Mei Zhang ◽  
...  

Nickel matrix and Si3N4 micron particles were co-deposited on the aluminum alloy by pulse electro-deposition for high temperature performance. Meanwhile, the oxidation resistance was evaluated through the high temperature oxidation test. The phase structure, micrographs and components of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS) respectively. The results indicated that Si3N4 particles were uniformly distributed across the coating and there were no pores and cracks or other defects at the coating/substrate interface. Ni-Si3N4 composite coatings are characterized by pyramidal micro-crystallite structure. The thickness of Ni-Si3N4 composite coatings were up to 80 μm for 2h. The results also revealed that the Ni-Si3N4 composite coatings presented better oxidation resistance than the pure Ni coating and aluminum alloy at high temperature. After oxidation at 673 K for 8h, the oxidation resistance of Ni-Si3N4 composite coatings presented the improved oxidation resistance behavior compared to pure Ni and the aluminum alloy, respectively.


CORROSION ◽  
1959 ◽  
Vol 15 (11) ◽  
pp. 73-77 ◽  
Author(s):  
JOHN F. RADAVICH

Abstract Growth of oxide films at 600 and 800 C on a series of 16 Cr-10 Ni-bal Fe stainless steels with silicon contents ranging from 0.17 to 3.55 percent was studied by electron microscopy, electron diffraction, X-ray diffraction and X-ray fluorescence analysis techniques. Oxide scales and sub-scales formed during oxidation at 1000 C were studied optically in cross section as well as by X-ray diffraction and fluorescence analysis. Results show that as silicon content increases oxidation resistance increases rapidly until at the high silicon level, 3.55 percent, a very thin oxide film is formed at 60u and 800 G and very little oxide scale forms at 1000 C. Mechanism of oxidation resistance imparted by silicon appears to be that it decreases the number of defects in the initial oxide films formed at the metal-oxide interface. With a lesser number of defects in the thin film, an enrichment of Cr at the metal-oxide interface and in the oxide films occurs and the rate of diffusion of iron outward to form the oxide scale is greatly retarded. 2.3.7


Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Shuaidan Lu ◽  
Xiaoxiao Li ◽  
Xiaoyu Liang ◽  
Wei Yang ◽  
Jian Chen

Alloying with V and Ti elements effectively improves the strength of WMoTaNb refractory high entropy alloys (RHEAs) at elevated temperatures. However, their effects on the oxidation resistance of WMoTaNb RHEAs are unknown, which is vitally important to their application at high temperatures. In this work, the effect of V and Ti on the oxidation behavior of WMoTaNb RHEA at 1000 °C was investigated using a thermogravimetric system, X-ray diffraction and scanning electron microscopy. The oxidation of all alloys was found to obey a power law passivating oxidation at the early stage. The addition of V aggravates the volatility of V2O5, MoO3 and WO3, and leads to disastrous internal oxidation. The addition of Ti reduces the mass gain in forming the full coverage of passivating scale and prolongs the passivation duration of alloys.


1994 ◽  
Vol 364 ◽  
Author(s):  
Guohua Qiu ◽  
Jiansheng Wu ◽  
Lanting Zhang ◽  
Dongliang Lin

AbstractA disadvantage to the application of Ti3Al is its poor high temperature oxidation resistance. It is found that the element Nb or(and) Si can greatly reduce the oxidation rate of Ti3A1. A hot stage in situ X-ray diffractometer was used to determine the formation sequence of the oxide layers. At 800°C, TiO2 as well as Al2O3 was detected on the surface of binary Ti3Al at the beginning of the oxidation process. The addition of 5 at % Si to Ti3Al alloy did not favor the formation of an A12O3 layer. On the contrary, it inhibited the onset of Al2O3 to nearly 20 hours from the start of the oxidation process at the temperature of 800°C. The Nb addition also did not promote the formation of Al2O3. TiO2 formed first on the surface of Ti3Al-11 at % Nb alloy while TiN and TiAl formed consequently. Al2O3 was further delayed to 20 hours from the beginning of the oxidation process. When the Nb addition increased to 15 at %, however, TiN and TiAl were not found. It is suggested that the favorable effect of Nb and Si to the oxidation resistance of Ti3Al alloy is not due to their promotion of A12O3 layer, but probably due to some other mechanisms, such as the formation of TiN which serves as a diffusion barrier and decreases porosity in the TiO2 layer.


1995 ◽  
Vol 396 ◽  
Author(s):  
Setsuo Nakao ◽  
Kazuo Saitoh ◽  
Masami Ikeyama ◽  
Hiroaki Niwa ◽  
Seita Tanemura ◽  
...  

AbstractAmorphous (a-) Ge films were deposited on air-cleaved CaF2 (111) substrates at different deposition temperatures (Td). The films were irradiated with 0.9 MeV Ge or Si ions at low ion current intensity (1c) l00nA/cm2. Their structural changes were studied by Rutherford backscattering spectrometry (RBS) -channeling technique and thin film x-ray diffraction (XRD) measurement. It was found that the films were epitaxially crystallized by Ge and Si ion irradiation although they included randomly oriented grains. Ge ion irradiation was more effective for the crystallization than Si ion irradiation. However, the amount of the randomly oriented grains was slightly higher when using Ge ions. On the other hand, ion irradiation to the films prepared at high Td also exhibited higher incidence of randomly oriented grains.


2014 ◽  
Vol 1035 ◽  
pp. 134-137
Author(s):  
Zhen Ting Wang ◽  
Shi Kui Zhu

In order to overcome the occurrence of insufficient oxidation reaction, high temperature oxidation resistance (ZrB2-SiC)/Si composite coating was fabricated on the surface of graphite electrode by argon arc cladding, process using the Si, Zr and B4C power blends. The microstructure and phase composition of the clad layer were researched by means of scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The result shows that the coating consist of ZrB2 and SiC particles, The combination of the cladding layer and the graphite matrix results in kind of a continuous interface without visible defects. As the result of burning 60 min at 1573K, the oxidation weightlessness rate is 0.62%.


2007 ◽  
Vol 546-549 ◽  
pp. 1485-1488 ◽  
Author(s):  
Shi Yu Qu ◽  
Ya Fang Han ◽  
Jin Xia Song ◽  
Yong Wang Kang

The effects of Cr and Al on high temperature oxidation resistance of Nb-Si system intermetallics have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and weight gain method. The results showed that the high temperature oxidation resistance can be substantially improved by proper Cr or Al addition. The further analysis revealed that Cr promotes the formation of CrNbO4 in scale and improve the adherence between the oxide scale and the substrate. It also found that Al improves the surface morphology of oxide scale and changes oxidation products by promoting the AlNbO4 formation.


Author(s):  
Liang Wu ◽  
Yifeng Xiao ◽  
Xiuyan Xia ◽  
Jinwen Qian ◽  
Yuehui He

Abstract The oxidation behavior of porous Ni-Cr-Fe materials prepared by reactive powder synthesis with different open porosity was studied in air at 6008C, 800 8C and 1 0008C. The differences in surface morphology, phase and pore structure parameters between material oxidized and non-oxidized were characterized by means of scanning electron microscopy, X-ray diffraction analysis and mercury intrusion. The results show that the oxidation rate of the samples which were oxidized at 600 8C for 340 h, for 560 h at 800 8C and for 560 h at 1 000 8C were 0.00027%2 h-1, 0.0558%2 h-1, and 0.64412%2 h-1, respectively. All the oxidation kinetics curves obeyed the parabolic law, exhibiting excellent high temperature oxidation resistance.


1994 ◽  
Vol 364 ◽  
Author(s):  
I-Chung Hsu ◽  
Shyi-Kaan Wu ◽  
Ray Yang Lin

AbstractTiAl binary intermetallics were aluminized in a vacuum system in order to improve their oxidation resistance. From the observations of optical microscopy and EPMA line scan, several different reaction layers were observed to be formed on respective substrates: pure Ti, Ti-32at.%Al, Ti-50at.%Al. From the results of the X-ray diffraction, the primary reaction layers were identified as TiAl3 structure in these three substrates This reacted layer grows with preferred orientation having [002] axis of TiAl3 perpendicular to the substrate surface from XRD experiments. High temperature oxidation tests revealed that vacuum aluminized layer was responsible for remarkable improvement on the oxidation resistance.


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