scholarly journals High Temperature Corrosion Behaviors of 20G Steel, Hastelloy C22 Alloy and C22 Laser Coating under Reducing Atmosphere with H2S

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 617 ◽  
Author(s):  
Zongde Liu ◽  
Congcong Liu ◽  
Yuan Gao ◽  
Chao Zheng

High-temperature corrosion behaviors of 20G steel, Hastelloy C22 alloy and C22 laser coating was evaluated by corrosion mass gain measurements at 450 °C. The corrosive atmosphere is 0.2 vol% H2S–0.1 vol% O2–N2, which simulated the severe high-temperature corrosion environment occurred under low-NOx combustion in pulverized-coal furnaces. Experimental results showed that the corrosion resistance of the C22 laser coating and the C22 alloy was obviously better than 20G steel. Furthermore, it should be noted that the C22 laser coating fabricated in this study displayed a higher corrosion resistance than the commercial C22 alloy although they had the same chemical composition. The severe pitting corrosion was observed in 20G steel with the corrosion products consisting of FeS2, Fe2O3 and Fe3O4. The C22 alloy and C22 laser coating exhibited the uniform corrosion and their main corrosion products were NiS2, CrS and a small amount of chromium and manganese oxides.

2013 ◽  
Vol 718-720 ◽  
pp. 52-58
Author(s):  
Sheng Huan Sang ◽  
Yu Feng Duan ◽  
Hui Chao Chen ◽  
Chang Sui Zhao

Corrosion experiments were carried out with metals 20G, 15CrMoG and 12Cr1MoVG under the simulated atmosphere (N2-5%O2-1500μL/L HCl) of superheaters in waste plastic boilers to choose appropriate materials preventing high temperature corrosion. Corrosion dynamic curves were plotted by mass gain per unit area. Metal specimens after corrosion tests were analyzed by SEM-EDS and XRD. The results show that 20G has the poorest anti-corrosion abilities among the three materials; the corrosion process is involved in activation oxidation of chlorine. Addition of Cr in alloys can improve their corrosion resistance in the mixed atmosphere.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5119
Author(s):  
Ibrahim A. Alnaser ◽  
Mohammed Yunus ◽  
Rami Alfattani ◽  
Turki Alamro

Various thermal spraying approaches, such as air/atmospheric plasma spraying (APS) and high-velocity oxy-fuel (HVOF) spraying, are widely employed by plants owing to their flexibility, low costs and the high surface quality of the manufactured product. This study focuses on the corrosion behavior of a Ni superalloy coated with powder Cr3C2-25NiCr through APS and HVOF at 950 °C under air oxidation and Na2SO4 + 0.6V2O5 molten salt environments (MSE). The results show that HVOF-deposited Ni superalloys have higher hardness and bond strength than the respective APS coating. The thermo-gravimetric probe reveals that the Ni superalloys exposed to an oxidizing air environment has a minor mass gain compared to those under the MSE domain for both non-coated and coated samples, in line with the parabola curvature rate oxidizing law. The Ni superalloys show good corrosion resistance but poor oxidation resistance in APS-deposited Ni superalloys under the MSE. HVOF-coated Ni superalloys in both environments exhibit better corrosion resistance and lower mass gain than APS-coated superalloys. The excellent coating characteristics of HVOF-coated Ni superalloys lead to their better high-temperature corrosion performance than APS.


Alloy Digest ◽  
1972 ◽  
Vol 21 (10) ◽  

Abstract INCONEL ALLOY 671 is a nickel-chromium alloy having excellent resistance to high-temperature corrosion. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-180. Producer or source: Huntington Alloy Products Division, An INCO Company.


Alloy Digest ◽  
1982 ◽  
Vol 31 (6) ◽  

Abstract Type HN is an iron-chromium-nickel alloy containing sufficient chromium for good high-temperature corrosion resistance and with nickel content in excess of the chromium. This alloy has properties somewhat similar to the more widely used ACI Type HT alloy but with better ductility. Type HN is used for highly stressed components in the 1800-2000 F temperature range. It is used in the aircraft, automotive, petroleum, petrochemical and power industries for a wide range of components and parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-410. Producer or source: Various stainless steel casting companies.


Author(s):  
T. Sand ◽  
A. Edgren ◽  
C. Geers ◽  
V. Asokan ◽  
J. Eklund ◽  
...  

AbstractA new approach to reduce the chromium and aluminium concentrations in FeCrAl alloys without significantly impairing corrosion resistance is to alloy with 1–2 wt.% silicon. This paper investigates the “silicon effect” on oxidation by comparing the oxidation behavior and scale microstructure of two FeCrAl alloys, one alloyed with silicon and the other not, in dry and wet air at 600 °C and 800 °C. Both alloys formed thin protective oxide scales and the Cr-evaporation rates were small. In wet air at 800 °C the Si-alloyed FeCrAl formed an oxide scale containing mullite and tridymite together with α- and γ-alumina. It is suggested that the reported improvement of the corrosion resistance of Al- and Cr-lean FeCrAl’s by silicon alloying is caused by the appearance of Si-rich phases in the scale.


2019 ◽  
Vol 66 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Somrerk Chandra-Ambhorn ◽  
Neramit Krasaelom ◽  
Tummaporn Thublaor ◽  
Sirichai Leelachao

Purpose This study aims to apply the pack cementation to develop the Fe-Al layers on the surface of FC 25 cast iron in order to increase the high-temperature corrosion resistance of the alloy. Design/methodology/approach Pack cementation was applied on the surface of FC 25 cast iron at 1,050°C. The bare and aluminised alloys were subjected to the oxidation test in 20 per cent O2-N2 at 850 °C. Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used for characterisation. Findings The layers of pack cementation consisted of Fe2Al5, FeAl2 and FeAl, and solid solution alloyed with Al. The oxidation kinetics of the bare cast iron was parabolic. Mass gain of the aluminised cast iron was significantly decreased compared with that of the bare cast iron. This was because of the protective alumina formation on the aluminised alloy surface. Al in the Fe–Al layer also tended to be homogenised during oxidation. Originality/value Even though the aluminising of alloys was extensively studied, the application of that process to the FC 25 cast iron grade was originally developed in this work. The significantly reduced mass gain of the aluminised FC 25 cast iron makes the studied alloy be promising for the use as a valve seat insert in an agricultural single-cylinder four-stroke engine, which might be run by using a relatively cheaper fuel, i.e. LPG, but as a consequence requires the higher oxidation resistance of the engine parts.


2019 ◽  
Vol 70 (6) ◽  
pp. 1071-1086 ◽  
Author(s):  
Gregor Mori ◽  
Karl J. Vidic ◽  
Edith Bucher ◽  
Muhammad Yasir ◽  
Daniel Hornauer ◽  
...  

2013 ◽  
Vol 212 ◽  
pp. 137-140 ◽  
Author(s):  
Janusz Cebulski ◽  
Stanisław Lalik

The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe-40Al-5Cr-0.2Ti-0.2B. Corrosion tests were conducted in temperatures from 600 to 900°C in time from 2 to 64 hours. Conducted tests have shown a slight increase of weight of samples in periods of time which followed. Increase of weight is connected with corrosion products in the form of passive oxides which form on the surface of the alloy. Kinetics of corrosion processes has parabolic course in tested temperature range which proves the formation of passive layers of corrosion products on the surface of samples. Heat resistance of the alloy on intermetallic phase matrix FeAl brings about potential possibilities to apply this alloy as a material meant for work in elevated and high temperatures in the environment which includes oxygen.


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