scholarly journals High-Temperature Oxidation Performance of 4Cr4Mo2NiMnSiV Hot Die Steel

2021 ◽  
Author(s):  
Renheng HAN ◽  
Ning LI ◽  
Ziming BAO ◽  
Xinjian HU ◽  
Hexin ZHANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Metallic Matrix ◽  
Oxidation Mechanism ◽  
Surface Oxidation ◽  
Ambient Atmosphere ◽  
Temperature Oxidation ◽  
Die Steel ◽  
Hot Working Die Steel

A new type of hot working die steel was designed by using JMatPro, and high-temperature oxidation tests were carried out in the ambient atmosphere at 600 ℃ and 700 ℃. The heat treatment process and oxidation mechanism of the designed 4Cr4Mo2NiMnSiV steel were studied in detail. XRD, SEM and EDS were used to analyze the crystallographic phases, surface and cross-section morphologies of the oxide films. The results show that the main phases in the 4Cr4Mo2NiMnSiV steel were γ and α + δ. During the high-temperature oxidation, oxidation of the Fe outer layer and Cr inner layer occurred. After oxidation at 600℃, the surface oxidation layer comprised a monolayer with an uneven morphology. The surface oxide film had two layers after oxidation at 700℃. The outer oxide layer mainly contained Fe2O3 and Fe3O4, while the inner oxide layer mainly contained Cr2O3. The microstructure was relatively regular and had a significant effect on the protection of the metallic matrix. When oxidized, the 4Cr4Mo2NiMnSiV alloy steel easily formed protective layers, such as Cr2O3 and SiO2, so that the test steel had excellent oxidation resistance at high temperatures.

High Temperature Oxidation Mechanism of TiAl-W-Si Alloys

2004 ◽  
Vol 449-452 ◽  
pp. 817-820 ◽  
Author(s):  
Dong Bok Lee ◽  
Seung Wan Woo
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Mixed Layer ◽  
Barrier Layer ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
Temperature Oxidation ◽  
Outward Diffusion

The oxidation of Ti-(43~52%)Al-2%W-(0~0.5%)Si alloys between 900 and 1050°C in air progressed via the outward diffusion of Ti ions to form the outer TiO2layer, and the inward transport of oxygen to form the inner (TiO2+Al2O3) mixed layer, between which the intermediate Al2O3barrier layer existed. Tungsten tended to diffuse inward to be incorporated below the intermediate Al2O3layer, while Si outward to exist over the entire oxide layer. Both W and Si tended to be dissolved in the oxide layer, rather than forming independent oxides.

scholarly journals Change of Oxidation Mechanisms by Laser Chemical Machined Rim Zone Modifications of 42CrMo4 Steel

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3910
Author(s):  
Alexander Schupp ◽  
René Daniel Pütz ◽  
Oliver Beyss ◽  
Lucas-Hermann Beste ◽  
Tim Radel ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Manufacturing Process ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
Metallic Surface ◽  
Temperature Oxidation ◽  
In Situ Xrd ◽  
42Crmo4 Steel ◽  
Oxidation Properties

The oxidation mechanism of metals depends, among other factors, on the surface integrity. The surface and rim zone properties are often determined by the manufacturing process that was used to machine the material. Laser chemical machining (LCM) is a manufacturing process that uses laser radiation as a localized and selective heat source to activate a chemical reaction between an electrolyte and a metallic surface. The objective of this work is first to investigate how different LCM processes affect the rim zone properties of 42CrMo4. For this purpose, the surface chemistry is analyzed by EDS and XPS, phases and residual stresses are determined by XRD, and the morphology is investigated by SEM. Second, the influence of these modified rim zones on the oxidation properties of the steel at 500 °C in air is to be demonstrated in oxidation tests by in situ XRD and subsequent SEM/EDS investigations. A decisive influence of the oxides formed on the surface of 42CrMo4 during LCM in different electrolytes (NaNO3 solution and H3PO4) at two different laser powers on the high-temperature oxidation properties was demonstrated. These oxides were supposed to act as nucleation sites for oxide layer formation at 500 °C and led to an overall increase in oxide layer thickness after high-temperature oxidation compared to non-LCM-processed surfaces.

High Temperature Oxidation Mechanism of Ti3SiC2-64vol%SiC Ceramics

2009 ◽  
Vol 24 (4) ◽  
pp. 821-826
Author(s):  
Hui-Yi TANG ◽  
De-Gui ZHU ◽  
Bo LIU ◽  
Hong-Liang SUN
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
Temperature Oxidation ◽  
Sic Ceramics

scholarly journals High-Temperature Oxidation Properties and Microstructural Evolution of Nanostructure Fe-Cr-Al ODS Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 526
Author(s):  
Zhengyuan Li ◽  
Lijia Chen ◽  
Haoyu Zhang ◽  
Siyu Liu
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Microstructural Evolution ◽  
High Temperature Oxidation ◽  
Oxide Dispersion Strengthened ◽  
Al Alloy ◽  
Temperature Oxidation ◽  
X Ray ◽  
Plasma Sintering ◽  
Ods Alloys

The oxidation behavior and microstructural evolution of the nanostructure of Fe-Cr-Al oxide dispersion strengthened (ODS) alloys prepared by spark plasma sintering were investigated by high-temperature oxidation experiments in air at 1200 °C for 100 h. The formation of Al2O3 scale was observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) line scans. The oxidation rate of Fe-Cr-Al ODS alloys is lower than that of conventional Fe-Cr-Al alloys, and the oxide layer formed on the Fe-Cr-Al alloy appeared loose and cracked, whereas the oxide layer formed on the Fe-Cr-Al ODS alloys was adherent and flat. This is due to the high density of dispersed nano-oxides hindering the diffusion of Al element and the formation of vacancies caused by them. In addition, the nano-oxides could also adhere to the oxide layer. Besides, the microstructure of the Fe-Cr-Al ODS alloy had excellent stability during high-temperature oxidation.

scholarly journals Effect of Nb addition on high-temperature oxidation behavior, oxide layer structure, and its exfoliation resistance of Ti-Nb Alloys

2020 ◽  
Vol 321 ◽  
pp. 05018
Author(s):  
Eri Miura-Fujiwara ◽  
Yuya Ogawa ◽  
Mitsuo Niinomi ◽  
Tohru Yamasaki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Interfacial Microstructure ◽  
Temperature Oxidation ◽  
Transmission Electron ◽  
Cp Ti ◽  
Nb Addition

The authors proposed an oxide coating on Ti alloys for the dental abutment tooth, and they had reported that Ti–29Nb–13Ta–4.6Zr (TNTZ) alloy forms a dense oxide layer by high-temperature oxidation. On the other hand, CP Ti forms a multilayered oxide consisted of rutile monolayers and the void layer. This morphological change by alloying is supposed to be mainly caused by Nb addition in Ti since the dense oxide layer of TNTZ mainly consists of rutile TiO2 and TiNb2O7. Therefore, in this study, oxidation behaviors of various range of Nb content of Ti-xNb alloys (x = 1 ~ 32 mol%) were investigated, and exfoliation resistance was evaluated. And in this paper, the oxide/metal interfacial microstructure of oxidized CP Ti, TNTZ alloy, and Ti-Nb alloy was studied by a transmission electron microscopy (TEM) and by a scanning transmission electron microscopy with an electron dispersive spectroscopy (STEM-EDS). The cross-sectional observations suggested that the substrate was gradually oxidized during heat treatment, and nucleation and grain growth of TiO2 and TiNb2O7 proceed at the metal/oxide interface. Consequently, the gradual oxidation process in TNTZ and Ti-Nb alloys could lead to its continuous interfacial microstructure and dense oxide structure, which can achieve high exfoliation resistance.

Oxidation of Tantalum Nitride

2013 ◽  
Vol 761 ◽  
pp. 125-129 ◽  
Author(s):  
Kazuya Hamaguchi ◽  
Tomoyuki Tsuchiyama ◽  
Junichi Matsushita
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Human Body ◽  
Body Fluid ◽  
High Temperature Oxidation ◽  
Tantalum Oxide ◽  
Mass Gain ◽  
Tantalum Nitride ◽  
Oxidation Temperature ◽  
Temperature Oxidation

Tantalum (Ta) can be use a suture for operation and implant material in order not to react with body fluid and stimulate a human body. In this study, the stable oxide of a tantalum, tantalum oxide layer produced by oxidation of the tantalum nitride, TaN powders by high temperature oxidation were investigated in order to determine the possibility of its a distributed aid for biomaterial composite such as an artificial root etc. The sample, TaN powder oxidized at high temperature exhibited a steady mass gain with increasing oxidation temperature. Based on the results of the XRD, tantalum oxide, Ta2O5 was detected on the samples. It is considered, the TaN showed a good oxidation film produced by high temperature oxidation.

High-Temperature Oxidation Behaviors of 30Cr25Ni20Si Heat-Resistant Steel in Air

2020 ◽  
Vol 861 ◽  
pp. 83-88
Author(s):  
You Yang ◽  
Xiao Dong Wang
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
High Temperature Oxidation ◽  
Film Growth ◽  
Surface Oxidation ◽  
Mass Gain ◽  
Resistant Steel ◽  
Temperature Oxidation ◽  
Heat Resistant Steel ◽  
Heat Resistant

High temperature oxidation dynamic behaviors and mechanisms for 30Cr25Ni20Si heat-resistant steel were investigated at 800, 900 and 1000°C. The oxide layers were characterized by scanning electron microscopy (SEM-EDS), X-ray diffractometer (XRD). The results showed that the oxidation rate of test alloys is increased with increasing the oxidation time. The oxidation dynamic curves at 800 and 900°C follow from liner to parabolic oxidation law. The transition point is 10 h. At 1000°C, the steel exhibits a catastrophic oxidation, and the oxidation mass gain value at 50 h is 0.77 mg/cm2. This suggests that the steel at 900°C has formed a dense protective surface oxidation film, effectively preventing the diffusion of the oxygen atoms and other corrosive gas into the alloy. Therefore, at the first stage of oxidation, chemical adsorption and reaction determine the oxide film composition and formation process. At the oxide film growth stage, oxidation is controlled by migration of ions or electrons across the oxide film. When the spinel scale forms, it acts as a compact barrier for O element and improving the oxidation resistance.

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