Superheated Steam Of Zirconium Alloys Containing Small Amounts Of Iron and Copper or Nickel

CORROSION ◽  
1965 ◽  
Vol 21 (4) ◽  
pp. 113-124 ◽  
Author(s):  
S. GREENBERG ◽  
C. A. YOUNGDAHL

Abstract Alloys of zirconium containing small amounts of iron and copper or nickel have corrosion resistance in superheated steam superior to that of the Zircaloys. At 540 C (1004 F) and 600 psi lowest rates are about 4 mdd (2.4 mpy) and at 650 C (1202 F) and 600 psi rates are about 6.8 mdd (4.1 mpy). High initial rates lead to an extrapolated intercept of about 4 mg/sq cm at 650 C (1202 F). The thickening films are subject to cracking at sharp radii. Absorption of corrosion product hydrogen decreases markedly as exposure temperature is raised from 540 to 650 C (1004 to 1202 F). This phenomenon is not understood. Metal embrittlement due to oxygen absorption becomes an increasingly serious problem as temperature is raised. Corrosion rate at 650 C (1202 F) is not affected by flow rate (300 ft/sec) or by presence of oxygen or oxygen-hydrogen mixtures in the steam.

1983 ◽  
Vol 28 ◽  
Author(s):  
T.D. Burleigh ◽  
R.M. Latanision

ABSTRACTPhosphorous has been shown to have a beneficial effect on reducing the corrosion rate of various metal alloys. This research was undertaken to determine by what mechanism the phosphorous is able to improve the corrosion resistance of metals. The amorphous copper-zirconium system was chosen for experimentation because the amorphous structure eliminates the complications due to crystalline defects. The zirconium forms zirconia (ZrO2), which is normally a protective surface oxide. Copper-zirconium alloys with and without phosphorous were melt-spun, and were tested in various electrolytes. In comparing Cu-42Zr-2P with Cu-4OZr, the results show that the corrosion rate of Cu-42Zr-2P is lower in 1N sulfuric acid, and significantly lower in 3.5 w/o NaCl, and in 1N HCl. ESCA analysis shows that phosphorous is present in the zirconia film, and has a valence of +5. Photocurrent experiments suggest that phosphorous alters the semiconductor properties of the zirconia film.


2014 ◽  
Vol 61 (3) ◽  
pp. 166-171 ◽  
Author(s):  
Yuan Lu ◽  
Ying Zhang ◽  
Zhenguo Liu ◽  
Yong Zhang ◽  
Chaoming Wang ◽  
...  

Purpose – In order to solve the corrosion problems in the South China Sea, the purpose of this paper was to study the main influences of corrosion including temperature, H2S content and corrosion inhibitor content in CO2/H2S oil field-produced water. Design/methodology/approach – The corrosion products formed on the steel surface were observed and analyzed using scanning electron microscope (SEM) and X-ray diffraction (XRD). Findings – The results indicate that temperature significantly influences the corrosion rate, which is a maximum at 70°C. The corrosion rate decreases as H2S content increases which is less than 10 mg/L, but then it increases rapidly. The FeCO3/Fe x S y protective film and a corrosion inhibition also were considered. Research limitations/implications – A mixture containing an imidazoline derivate and an organic amine can enhance the corrosion resistance of the corrosion product film. Practical implications – A mixture containing an imidazoline derivate and an organic amine can enhance the corrosion product film corrosion resistance. Social implications – Imidazoline is one kind of environmentally safe agent which can be used in the ocean. Originality/value – The corrosion can be controlled to a satisfactory extent in the presence of a mixture containing an imidazoline derivate and an organic amine.


Alloy Digest ◽  
1963 ◽  
Vol 12 (8) ◽  

Abstract Cooper Alloy 22W is a high strength, heat resistant casting alloy with a low creep rate. It is recommended for heat applications where stress and hot gas corrosion rate are very high. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SS-146. Producer or source: Cooper Alloy Corporation.


2012 ◽  
Vol 48 (9) ◽  
pp. 1097 ◽  
Author(s):  
Meiyi YAO ◽  
Linghong ZOU ◽  
Xingfei XIE ◽  
Jinlong ZHANG ◽  
Jianchao PENG ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 517
Author(s):  
Bin Sun ◽  
Lei Cheng ◽  
Chong-Yang Du ◽  
Jing-Ke Zhang ◽  
Yong-Quan He ◽  
...  

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.


2021 ◽  
Vol 2 (1) ◽  
pp. 61-77
Author(s):  
Hamid Reza Jafari ◽  
Ali Davoodi ◽  
Saman Hosseinpour

In this work, the corrosion behavior and surface reactivity of as-cast and heat-treated nickel aluminum bronze casting alloy (UNS C95800) in 3.5 wt% NaCl solution is investigated under stagnant and flow conditions. Increasing flow rate conditions are simulated using a rotating disk electrode from 0 to 9000 revolutions per minute (rpm). Optical micrographs confirm the decrease in the phase fraction of corrosion-sensitive β phase in the microstructure of C95800 after annealing, which, in turn, enhances the corrosion resistance of the alloy. Electrochemical studies including open circuit potentiometry, potentiodynamic polarization, and electrochemical impedance spectroscopy are performed to assess the effect of flow rate and heat treatment on the corrosion of samples at 25 and 40 °C in 3.5 wt% NaCl solution. For both as-cast and heat-treated samples, increasing the flow rate (i.e., electrode rotating rate) linearly reduces the corrosion resistance, indicating that the metal dissolution rate is significantly affected by hydrodynamic flow. Increasing the solution temperature negatively impacts the corrosion behavior of the as-cast and heat-treated samples at all flow conditions.


2014 ◽  
Vol 896 ◽  
pp. 245-248 ◽  
Author(s):  
Candra Kurniawan ◽  
Hayati M.A. Sholihat ◽  
Kemas Ahmad Zaini Thosin ◽  
Muljadi ◽  
Prijo Sardjono

Despite of its excellence magnetic quality, one of the critical properties of PrFeB based permanent magnet is a low corrosion resistance so it can be oxidized easily which can reduce its magnetic properties. In this study, Nickel coating has been performed for bonded PrFeB magnet by the electroplating method using Nickel-Watts bath-type as the electrolyte to improve the corrosion resistance. The varying amount of the electrolyte compounds used to have the optimized composition indicated by the corrosion resistance measurement. The solution composition used was NiSO4 (230-380 g/L), NiCl2 (30-60 g/L), and H3BO3 (30 and 45 g/L) with a fixed value of other parameters. Characterization used including the immersion corrosion test, microstructure analysis, and magnetic properties. Based on the corrosion rate measurement, the highest corrosion resistant of Nickel coated PrFeB magnet achieved from the electrolyte composition of NiSO4: NiCl2: H3BO3 = 380: 60: 30 g/L with a plating time and current density (J) of 60 minutes and 40 mA/cm2 respectively. The corrosion rate data showed that the Nickel metal coating can improve the corrosion resistance of bonded PrFeB magnet up to 29 times than of the substrate. The SEM images showed that the thickness of the Nickel coating on the optimum electrolyte composition was in average value of 35.1 µm. The overall samples has a magnetic remanence value (Br) reached ≥ 6 kG, so it has enough properties to be applied in devices such as generators and electric motors.


1970 ◽  
Vol 9 (9) ◽  
pp. 39-43
Author(s):  
Basu Ram Aryal ◽  
Jagadeesh Bhattarai

Simultaneous additions of tungsten, chromium and zirconium in the chromium- and zirconium-enriched sputter-deposited binary W-xCr and W-yZr are effective to improve the corrosion resistance property of the ternary amorphous W- xCr-yZr alloys after immersion for 240 h in 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter-deposited (10-57)W-(18-42)Cr-(25-73)Zr alloys is higher than those of alloy-constituting elements (that is, tungsten, chromium and zirconium) in aggressive 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter−deposited W–xCr–yZr alloys containing 10-57 at% tungsten, 18-42 at% chromium and 25-73 at% zirconium were in the range of 1.5-2.5 × 10−3 mm/y or lower which are more than two orders of magnitude lower than that of sputter-deposited tungsten and even about one order of magnitude lower than those of the sputter-deposited zirconium in 1 M NaOH solution. Keywords: Ternary W–Cr–Zr alloys; Amorphous; Corrosion rate; Open circuit potential; 1 M NaOH. DOI: http://dx.doi.org/10.3126/sw.v9i9.5516 SW 2011; 9(9): 39-43


Author(s):  
M. Y. Yao ◽  
B. X. Zhou ◽  
Q. Li ◽  
W. P. Zhang ◽  
L. Zhu ◽  
...  

In order to investigate systematically the effect of Bi addition on the corrosion resistance of zirconium alloys, different zirconium-based alloys, including Zr-4 (Zr-1.5Sn-0.2Fe-0.1Cr), S5 (Zr-0.8Sn-0.35Nb-0.4Fe-0.1Cr), T5 (Zr-0.7Sn-1.0Nb-0.3Fe-0.1Cr) and Zr-1Nb, were adopted to prepare the zirconium alloys containing Bi of 0∼0.5% in mass fraction. These alloys were denoted as Zr-4+xBi, S5+xBi, T5+xBi and Zr-1Nb+xBi, respectively. The corrosion behavior of these specimens was investigated by autoclave testing in lithiated water with 0.01 M LiOH or deionized water at 360°C/18.6 MPa and in superheated steam at 400 °C/10.3 MPa. The micro structure of the alloys was examined by TEM and the second phase particles (SPPs) were analyzed by EDS. Micro structure observation shows that the addition of Bi promotes the precipitation of Sn as second phase particles (SPPs) because Sn is in solid solution in α-Zr matrix in Zr-4, S5 and T5 alloys. The concentration of Bi dissolved in α-Zr matrix increase with the increase of Nb in the alloys, and the excess Bi precipitates as Bi-containing SPPs. The corrosion results show that the effect of Bi addition on the corrosion behavior of different zirconium-based alloys is very complicated, depending on their compositions and corrosion conditions. In the case of higher Bi concentration in α-Zr, the zirconium alloys exhibit better corrosion resistance. However, in the case of precipitation of Bi-containing SPPs, the corrosion resistance gets worse. This indicates that the solid solution of Bi in α-Zr matrix can improve the corrosion resistance, while the precipitation of the Bi-containing SPPs is harmful to the corrosion resistance.


2017 ◽  
Vol 13 (10) ◽  
pp. 5905-5913
Author(s):  
S. Saravanan ◽  
P.Senthil Kumar ◽  
T. Palanisamy ◽  
M. Ravichandran ◽  
V. Anandakrishnan ◽  
...  

AA6063-TiC composites have several weight percentages up to 9 wt. % were fabricated by using stir casting route method. The effects of the weight percentage of TiC particles on the microstructures and corrosion behavior of AA6063-TiC composites were studied. The results revealed that the AA6063-TiC composites exhibited higher density than the AA6063 matrix. The accelerated corrosion tests of AA6063-TiC composites in 3.5 wt. % NaCl aqueous solution at room temperature, the AA6063-TiC composites have better corrosion resistance than the AA6063 matrix. Increasing the weight percentage of the TiC particles to reduces the corrosion rate of the AA6063-TiC composites. In this process corrosion rate of 0.4402 mm/year for AA6063 matrix, 0.3891 mm/year for 3 wt. % , 0.3568 mm/year for 6 wt. % and 0.3062 mm/year for 9 wt. % of TiC particles respectively. The poor corrosion resistance of the composites can be attributed to the galvanic effects between the AA6063 matrix and TiC reinforcement.


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