Microstructure Characterization and Hot Corrosion Mechanism of As-cast and Heat Treated High Nb Containing TiAl alloy

2021 ◽  
pp. 109399
Author(s):  
Zhiping Sun ◽  
Wenqing Wu ◽  
Yongnan Chen ◽  
Zhanwei Yuan ◽  
Yongshuai Zhang ◽  
...  
Keyword(s):  
Hot Corrosion ◽  
Tial Alloy ◽  
Microstructure Characterization ◽  
Corrosion Mechanism ◽  
Heat Treated

Effect of Heat Treatment on the Microstructure and Property of TiAl Alloys Prepared by Gas Atomization Powders

2013 ◽  
Vol 747-748 ◽  
pp. 497-501
Author(s):  
Na Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Hua Yuan ◽  
Wen Yong Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Tial Alloy ◽  
Lamellar Microstructure ◽  
Treatment Temperature ◽  
Gas Atomization ◽  
Thermally Induced ◽  
Heat Treated ◽  
Fine Duplex ◽  
Step Heat Treatment

Powder metallurgical TiAl alloy was fabricated by gas atomization powders, and the effect of heat treatment temperature on the microstructure evolution and room tensile properties of PM TiAl alloy was investigated. The uniform fine duplex microstructure was formed in PM TiAl based alloy after being heat treated at 1250/2h followed by furnace cooling (FC)+ 900/6h (FC). When the first step heat treatment temperature was improved to 1360/1h, the near lamellar microstructure was achieved. The ductility of the alloy after heat treatment improved markedly to 1.2% and 0.6%, but the tensile strength decreased to 570MPa and 600MPa compared to 655MPa of as-HIP TiAl alloy. Post heat treatment at the higher temperature in the alpha plus gamma field would regenerate thermally induced porosity (TIP).

Chloride- and sulphate-induced hot corrosion mechanism of super austenitic stainless steel S31254 under dry gas environment

2020 ◽  
Vol 163 ◽  
pp. 108295 ◽  
Author(s):  
Shucai Zhang ◽  
Huabing Li ◽  
Zhouhua Jiang ◽  
Binbin Zhang ◽  
Zhixing Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Hot Corrosion ◽  
Corrosion Mechanism ◽  
Gas Environment ◽  
Super Austenitic Stainless Steel

A Study of Hot Corrosion of Fe-Cr Alloys Induced by a Thin Film of Fused (Na,K)2SO4 by Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 32 (5) ◽  
pp. 493-501
Author(s):  
S.N. Liu ◽  
W. Su ◽  
W.Y. Lu ◽  
Z.F. Wei ◽  
C.L. Zeng
Keyword(s):  
Thin Film ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Hot Corrosion ◽  
Electrochemical Impedance ◽  
Diffusion Flux ◽  
Electrode System ◽  
Corrosion Mechanism ◽  
Low Frequencies ◽  
Nyquist Plots

AbstractTo understand the hot corrosion mechanism of materials it is of significance to establish electrochemical measurements under a thin film of fused salts. In this paper, the hot corrosion behavior of Fe-Cr alloys containing 5, 10 and 25wt% Cr, respectively, in the presence of a fused film of 0.9Na2SO4-0.1K2SO4 (mole fraction) at 1173 K in air has been investigated by electrochemical impedance spectroscopy using a two-electrode system. The Nyquist plots for the corrosion of both Fe-5Cr and Fe-10Cr are composed of a very small semicircle at high frequencies and a line at low frequencies indicating that the corrosion is controlled by the diffusion of oxidants in the fused salt film. The alloys were severely corroded, forming a thick porous corrosion layer containing large amounts of non-protective precipitated Fe oxide particles. Conversely, the Nyquist plots for the corrosion of Fe-25Cr are composed of double capacitive loops, with significantly larger impedance values, which are associated with the formation of a protective Cr2O3 scale. Based on the experimental diffusion impedance results and the theoretic solubility and diffusion coefficient of oxygen in molten salts, respectively, a theoretical value of the diffusion flux of molecular O2 has been calculated.

Effect of Al Y gradient coating on hot corrosion resistance of γ-TiAl alloy at different temperatures

2019 ◽  
Vol 487 ◽  
pp. 868-875 ◽  
Author(s):  
Hao Lin ◽  
Wenping Liang ◽  
Yanlin Jia ◽  
Qiang Miao ◽  
Rongyao Hu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Tial Alloy ◽  
Gradient Coating ◽  
Different Temperatures

MICROSTRUCTURE CHARACTERIZATION AND STRENGTH ASSESSMENT OF A HEAT-TREATED SELECTIVE LASER MELTED 300-GRADE MARAGING STEEL

2019 ◽  
Author(s):  
Fabio Conde ◽  
Waldek Wladimir Bose Filho ◽  
Julian Escobar ◽  
André Tschiptschin ◽  
André Jardini ◽  
...  
Keyword(s):  
Maraging Steel ◽  
Microstructure Characterization ◽  
Strength Assessment ◽  
Heat Treated

Hot corrosion behavior of electrodeposited SiO2 coating on TiAl alloy

2020 ◽  
Vol 174 ◽  
pp. 108827
Author(s):  
Lian-Kui Wu ◽  
Jing-Jia Wu ◽  
Wei-Yao Wu ◽  
Hao-Jie Yan ◽  
Mei-Yan Jiang ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Tial Alloy ◽  
Sio2 Coating

Influence of heat treatment on corrosion behavior of laser welded Mg-Gd-Y fusion zones

2020 ◽  
Vol 67 (4) ◽  
pp. 337-343
Author(s):  
Lyuyuan Wang ◽  
Jian Huang ◽  
Yong Peng ◽  
Yang Jia ◽  
Rong Ni
Keyword(s):  
Corrosion Resistance ◽  
Fusion Zone ◽  
Corrosion Behavior ◽  
Corrosion Mechanism ◽  
Content Type ◽  
Treated Condition ◽  
Heat Treated ◽  
Protective Films ◽  
Heat Treated Condition ◽  
Treated State

Purpose This paper aims to evaluate the corrosion resistance of fusion zones in different heat treated condition from laser welded Mg-Gd-Y alloys and analyze their intrinsic corrosion mechanism. Design/methodology/approach The corrosion behavior of fusion zone from laser-welded Mg-Gd-Y alloy joints in the as-welded, ageing and solution + ageing conditions was investigated in the 3.5 wt.% NaCl solution by immersion tests. Findings The corroded surface of as-welded fusion zone consists of dark and bright regions, and the bright regions were composed of high-density needle-like products, whereas some different extended direction of the cracks with lots of long ultrafine needle-shaped corrosion products appeared in the dark regions. The corrosion resistance of the fusion zone is slightly decreased after the ageing treatment. Originality/value The solution + ageing treated fusion zone exhibits the highest corrosion resistance than that of the as-welded and ageing treated state because of the full dissolution of the cathodic coarse eutectic compound, grains growth and relatively compact protective films. The inhomogeneous distribution of the β′ can somewhat improve the corrosion rate of solution + ageing treated fusion zone when compared with base metal.

Hot-corrosion mechanism of Ni-Cr coatings at 650°C under different simulated corrosion conditions

2008 ◽  
Vol 18 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Xue-mei OU ◽  
Zhi SUN ◽  
Min SUN ◽  
Duan-lian ZOU
Keyword(s):  
Hot Corrosion ◽  
Corrosion Mechanism
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