scholarly journals Some Manifestations of Antioxidation Coating for Hot Precision Forging Gears

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Dongcheng Li ◽  
Nana Han ◽  
Luca Quagliato ◽  
Naksoo Kim ◽  
Ge Yu
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Hot Forging ◽  
Dimensional Accuracy ◽  
Coated Sample ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Uncoated Sample ◽  
Precision Forging ◽  
High Temperature Oxidation Behavior

A high temperature protective coating was prepared onto the surface of 20CrMnTi steel by brushing technique, and the heated billet was subjected to hot forging. Compared with an uncoated sample, the effect of coating on high-temperature oxidation behavior of steel was investigated by scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction. Before hot forging, an oxide layer of 153 μm was formed on the surface of the uncoated sample; however, no oxide layer was formed on the surface of the coated sample. After hot forging, the thickness of scale on the surface of uncoated gear forging is 89 μm while the thickness of coating on the surface of coated gear forging is 39 μm. It is concluded that such a coating material not only enhances the dimensional accuracy but also improves the surface quality of the gear.

scholarly journals High Temperature Anti-Oxidation Behavior and Mechanical Property of Radio Frequency Magnetron Sputtered Cr Coating

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1509
Author(s):  
Guangbin Li ◽  
Yanhong Liu ◽  
Yingchun Zhang ◽  
Huailin Li ◽  
Xiaojing Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Radio Frequency ◽  
Oxidation Behavior ◽  
Zirconium Alloys ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
High Temperature Steam ◽  
High Temperature Oxidation Behavior ◽  
Cr Coating

A dense and uniform Cr coating was fabricated on the zirconium alloys fuel claddings by radio frequency (RF) magnetron sputtering to improve the mechanical and anti-oxidation properties under 1200 °C steam environment. The phase composition and the micro and macro morphologies of the specimens were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscope (SEM) and optical-microtopography (OM) analyses, and the high-temperature oxidation behavior was evaluated at 1200 °C steam environment for 3000 s. In this paper, there exists a positive correlation between thickness and Vickers hardness (HV), and a negative correlation between surface roughness and bonding force. Radial tensile was introduced to investigate the deformation-resistant performance, and the displacement of the Cr-coated specimen was as low as 2.32 mm, which was much lower than the uncoated zircaloy cladding (3.05 mm). Different thicknesses of Cr coatings were deposited to investigate the oxidation degrees of zircaloy cladding under a high-temperature steam environment. The optimal 6 μm Cr-coated zirconium alloys cladding exhibited an excellent anti-oxidation property, and the weight gain was as low as ~4.12 mg/cm2, which was almost one-third of the uncoated specimen.

High Temperature Oxidation Behavior of Arc-sprayed FeCrBAlMo Coating

2016 ◽  
Vol 19 (1) ◽  
Author(s):  
Xin Zhang ◽  
Zehua Wang ◽  
Jinran Lin
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Steel Substrate ◽  
Arc Spraying ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Velocity Arc Spraying ◽  
High Temperature Oxidation Behavior

AbstractFeCrBAlMo coating was deposited on an AISI 20 steel substrate by high velocity arc spraying (HVAS). Compared with FeCrBSiMo coating and pristine AISI 20 steel, the microstructure and high temperature oxidation behavior of FeCrBAlMo coating were investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Meanwhile, the bonding strength of the coatings was also measured. The results indicated that both coatings were composed of α(Fe,Cr) and Fe

Effect of Mo on the High Temperature Oxidation Behavior of Co-Al-W Based Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 754-759 ◽  
Author(s):  
Fei Fan ◽  
Hao Sun ◽  
Di Zhao ◽  
Jiang Bo Sha
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
Oxide Layer ◽  
Outer Layer ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Kinetic ◽  
Complex Oxide ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

2 at.% and 4 at.% Mo were added to Co-9Al-9W-2Ta-0.02B alloy to replace W (hereafter referred to as the alloys of 2Mo and 4Mo, respectively; Mo-free alloy was referred to as the 0Mo alloy). The effects of Mo additions on the high temperature oxidation behavior of the alloys at 800 °C in air have been studied. The results indicated that, after oxidation in air at 800 °C for 100 h, the oxide film of the 0Mo alloy remained intact, but the cracking and spallation of the oxide film took place in the alloys of 2Mo and 4Mo. Oxidation kinetic curves revealed weight gain per unit area of the 0Mo alloy was 36.86 mg·cm-2, which was lower than that of the alloys of 2Mo (65.16 mg·cm-2) and 4Mo (48.54mg·cm-2). These suggested that the 0Mo alloy displayed superior oxidation resistance compared to the alloys of 2Mo and 4Mo caused by the formation of volatile MoO3 oxide, and sharp compressive stress formed in the outer layer during the oxidation. The oxide layer was composed of three layers of the Co3O4 + CoO outer layer, middle complex oxide layer containing Co, Al and W (Mo), inner Al2O3 layer and γ/Co3W zone adhere to the γ/γ' substrate.

scholarly journals High Temperature Oxidation Behavior of an Equimolar Cr-Mn-Fe-Co High-Entropy Alloy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4259
Author(s):  
Lin Wang ◽  
Quanqing Zeng ◽  
Zhibao Xie ◽  
Yun Zhang ◽  
Haitao Gao
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
High Entropy Alloy ◽  
Spinel Type ◽  
Temperature Oxidation ◽  
Outward Diffusion ◽  
High Entropy ◽  
High Temperature Oxidation Behavior

The oxidation behavior of an equimolar Cr-Mn-Fe-Co high-entropy alloy (HEA) processed by 3D laser printing was investigated at 700 °C and 900 °C. The oxidation kinetics of the alloy followed the parabolic rate law, and the oxidation rate constant increased with the rising of the temperature. Inward diffusion of oxygen and outward diffusion of cations took place during the high-temperature oxidation process. A spinel-type oxide was formed on the surface, and the thickness of the oxide layer increased with the rising of experimental temperature or time. The exfoliation of the oxide layer took place when the test was operated at 900 °C over 12 h. During oxidation tests, the matrix was propped open by oxides and was segmented into small pieces. The formation of loose structures had great effects on the high-temperature oxidation resistance of the HEA.

High Temperature Oxidation Behavior of Si-Mo Ferritic Ductile Cast Iron

2010 ◽  
Vol 654-656 ◽  
pp. 542-545 ◽  
Author(s):  
Kyeong Hwan Choe ◽  
Sang Mok Lee ◽  
Kyong Whoan Lee
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Oxide Layer ◽  
Test Temperature ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Ductile Cast Iron ◽  
Ferrous Alloy ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

High temperature oxidation behavior of Si-Mo ferritic ductile cast iron was investigated in the point of the effect of chromium and vanadium addition. The addition of Cr promoted the formation of as-cast pearlite around carbide which exists in cell boundary, which was eliminated during annealing process. The addition of vanadium promoted the precipitation of tiny carbide and reduced the grain size of ferrite. As the test temperature increased, the change of volume increased, on the other hand, the change of weight decreased above 1173K. In the case of Cr added specimen, the change of weight decreased with the increase of test temperature because of the presence of Cr oxide layer. The vanadium added specimens showed higher increase in the weight and volume change. The oxide layer of vanadium added specimen had very porous structure and showed severe internal oxidation. It is due to the catastrophic oxidation characteristic of vanadium alloyed ferrous alloy.

High Temperature Oxidation Behavior of ZrB2-SiC-Graphite Composite Heated by High Electric Current

2010 ◽  
Vol 105-106 ◽  
pp. 162-164
Author(s):  
Hong Bo Chen ◽  
Song He Meng
Keyword(s):  
High Temperature ◽  
Electric Current ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Graphite Composite ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
Oxidation Testing

High temperature oxidation testing was carried out on hot-pressed ZrB2-SiC-graphite composite by using high electric current heating. The composites oxidation behavior was investigated, the temperature of oxidized specimens was above 2000°C. The results found that the UHTC composite was ruptured at oxidized temperature 2055°C. The microstructure of surface and cross-section of posttest samples were investigated by scanning electron microscopy along with energy and X-ray diffraction. The failure mechanism of rupture was also discussed.

Effect of WС Content on the Mechanical Properties and High Temperature Oxidation Behavior of Ti(С,N)-Based Cermets

2018 ◽  
Vol 274 ◽  
pp. 9-19
Author(s):  
Guo Tao Zhang ◽  
Yong Zheng ◽  
Yi Jie Zhao ◽  
Wei Zhou ◽  
Jia Jie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
Oxide Scales ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxidation Rates ◽  
High Temperature Oxidation Behavior

Ti (C,N)-based cermets with varying WC additions (Ti (C0.6N0.4)-36Ni-12Mo-1C-xWC, x = 0, 3, 6 and 9 wt%) were prepared by conventional powder metallurgy techniques. The microstructure and mechanical properties of all four Ti (C,N)-based cermets were investigated. Isothermal oxidation of all four cermets were also investigated in air at 800°C up to 100 h using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD). The grains of Ti (C,N)-based cermets became more homogeneous with the increase of WC content. The TRS and fracture toughness increased with the increase of WC content and then decreased when WC content exceeded 6wt%, but hardness decreased continuously with the increase of WC content. The oxide scales formed on the surface of all four samples during the oxidation process were porous and multi-layered, consisting of NiO outerlayer and TiO2 based innerlayer, respectively. The thickness of the oxide scales and oxidation rates increased with the increase of WC content, especially when the content of WC addition reached 9wt%. The cermet with 6wt% WC addition showed excellent mechanical properties and acceptable high temperature oxidation resistance.

Sign in / Sign up

Export Citation Format

Share Document