scholarly journals Effect of Chemistry Variations in Plate and Weld Filler Metal on the Corrosion Performance of Ni-Cr-Mo Alloys

2006 ◽  
Author(s):  
David V. Fix ◽  
Rau´l B. Rebak
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Filler Metal ◽  
Weight Percent ◽  
Corrosion Performance ◽  
Nickel Chromium ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Alloy 22 ◽  
G 28

The ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022) and Alloy 686 (N06686). The compositions of each element are given in a range. For example, the content of Mo is specified from 12.5 to 14.5 weight percent for Alloy 22 and from 15.0 to 17.0 weight percent for Alloy 686. It was important to determine how the corrosion rate of welded plates of Alloy 22 using Alloy 686 weld filler metal would change if heats of these alloys were prepared using several variations in the composition of the elements even though still in the range specified in B 575. All the material used in this report were especially prepared at Allegheny Ludlum Co. Seven heats of plate were welded with seven heats of wire. Immersion corrosion tests were conducted in a boiling solution of sulfuric acid plus ferric sulfate (ASTM G 28 A) using both as-welded (ASW) coupons and solution heat-treated (SHT) coupons. Results show that the corrosion rate was not affected by the chemistry of the materials in the range of the standards.

scholarly journals Effect of Small Variation in the Composition of Plates and Weld Filler Wires on the General Corrosion Rate of Ni-Cr-Mo Alloys

2005 ◽  
Author(s):  
David V. Fix ◽  
John C. Estill ◽  
Rau´l B. Rebak
Keyword(s):  
Corrosion Rate ◽  
Filler Metal ◽  
Small Variation ◽  
Weight Percent ◽  
General Corrosion ◽  
Nickel Chromium ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Alloy 22 ◽  
G 28

The ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022) and Alloy 686 (N06686). The compositions of each element are given in a range. For example, the content of Mo is specified from 12.5 to 14.5 weight percent for Alloy 22 and from 15.0 to 17.0 weight percent for Alloy 686. It was important to determine how the corrosion rate of welded plates of Alloy 22 using Alloy 686 weld filler metal would change if heats of these alloys were prepared using several variations in the composition of the elements even though still in the range specified in B 575. All the material used in this report were especially prepared at Allegheny Ludlum Co. Seven heats of plate were welded with seven heats of wire. Immersion corrosion tests were conducted in a boiling solution of sulfuric acid plus ferric sulfate (ASTM G 28 A) using both as-welded (ASW) coupons and solution heat-treated (SHT) coupons. Results show that the corrosion rate was not affected by the chemistry of the materials within the range of the standards.

scholarly journals Effect of Chemistry Variations of Wrought N06022 Plates on the Repassivation Potential in 1 M NaCl at 90°C

2008 ◽  
Author(s):  
Kevin G. Mon ◽  
Raul B. Rebak
Keyword(s):  
Chemical Composition ◽  
Potentiodynamic Polarization ◽  
Heat Treating ◽  
Weight Percent ◽  
Nacl Solution ◽  
Nickel Chromium ◽  
Repassivation Potential ◽  
Heat Treated ◽  
Alloy 22 ◽  
Cyclic Potentiodynamic Polarization

ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022). The composition of each element is given in a range (e.g., the lowest content of Mo is specified as 12.5 weight percent and the highest as 14.5 weight percent. It is important to determine the dependence of Alloy 22 electrochemical behavior on the composition of the alloying elements as they vary from the lowest to the highest end of the ranges specified in ASTM B 575 standard. Seven heats of Alloy 22 plate were melted and processed. The plates were tested in the mill annealed (MA) and solution heat treated (SHT) condition. Cyclic potentiodynamic polarization tests were performed in 1 M NaCl solution at 90°C. Results show no influence of Alloy 22 chemistry variations or heat treating on the measured repassivation potential.

Fabrication and Characterization of a Biocompatible Coating Formed on a Heat-Treated Magnesium Alloy Using Micro-Arc Oxidation

2017 ◽  
Author(s):  
Hamdy Ibrahim ◽  
Mohammad Elahinia
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Mg Alloys ◽  
Corrosion Tests ◽  
Bone Fixation ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Micro Arc Oxidation

The fast corrosion rate of magnesium (Mg) alloys is the main problem associated with the use of such biocompatible alloys for bone fixation applications. The corrosion resistance of Mg alloys can be improved by different post-fabrication processes such as heat treatment and coating. We have heat-treated a biocompatible Mg-1.2Zn-0.5Ca (wt.%) alloy at optimized heat treatment parameters to achieve the highest mechanical strength and corrosion resistance. Afterwards, the heat-treated alloy was coated with a ceramic layer using micro arc oxidation (MAO) process to further enhance the corrosion resistance. The microstructure of the prepared samples was investigated using optical microscopy and scanning electron microscopy (SEM). The corrosion characteristics were determined by conducting in vitro electrochemical and immersion corrosion tests. The results showed that the heat treatment process successfully improved the mechanical and corrosion properties of the Mg-1.2Zn-0.5Mn (wt.%) alloy. Both the in vitro electrochemical and immersion corrosion tests showed that the MAO-coated samples have a significantly higher corrosion resistance which results in a significantly lower corrosion rate. This study indicated that the biocompatible coating produced by MAO process may be suitable for providing heat-treated Mg-Zn-Ca-based alloys with protection from corrosion towards synthesizing bone fixation materials in clinical application.

Electrolyte Based Modeling of Corrosion Processes in Sulfuric Acid Mixtures – Part 1: Non-Oxidizing Conditions

CORROSION ◽  
10.5006/3872 ◽  
2021 ◽  
Author(s):  
Narasi Sridhar ◽  
Andrzej Anderko
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Weight Percent ◽  
Reaction Rates ◽  
Reduction Reaction ◽  
Proton Reduction ◽  
Mole Percent ◽  
Active Dissolution ◽  
Experimental Values ◽  
Electrochemical Model

The corrosion behavior of stainless steels and Ni-base alloys in non-oxidizing sulfuric acid mixtures at concentrations below approximately 30 moles/Kg H2O is modeled. The redox potential in sulfuric acid across a broad concentration range, from 0 to 80 mole percent (0 to 95.6 weight percent), is determined by the proton reduction reaction. Thus, in the absence of other oxidizing species, sulfuric acid behaves as a non-oxidizing (reducing) acid. The calculated corrosion rate, using an electrochemical model up to about 30 moles/Kg H2O (about 75 weight percent) is in agreement with experimental values. The predicted polarization curves of anodic and cathodic processes showed that the alloys in these environments are in active dissolution regime, consistent with experimental data. The model predictions of corrosion rates in H2SO4+HCl, H2SO4+HF, and H2SO4+HCl+HF mixtures are in agreement with weight-loss corrosion data. The corrosion rate of alloys in the non-oxidizing sulfuric acid mixtures correlated to an equivalent alloy composition given by (Ni0.7-Cr0.1+Mo+0.5W). The effect of alloying elements under these conditions may be related to their beneficial effect on active dissolution and proton reduction reaction rates.

HAYNES 556 ALLOY FILLER METAL

Alloy Digest ◽  
2000 ◽  
Vol 49 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Filler Metal ◽  
Cobalt Alloy ◽  
Nickel Chromium ◽  
Iron Nickel ◽  
Haynes Alloy ◽  
Alloy Filler

Abstract Haynes alloy 556 filler metal is an iron-nickel-chromium-cobalt alloy that combines effective resistance to sulfidizing, carburizing, and chlorine-bearing environments with excellent strength and oxidation resistance at high temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as joining. Filing Code: SS-782. Producer or source: Haynes International Inc.

AISI 9840

Alloy Digest ◽  
1957 ◽  
Vol 6 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Heat Treating ◽  
Good Combination ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Treated Condition ◽  
Heat Treated ◽  
Molybdenum Steel ◽  
Heat Treated Condition ◽  
Lower Nickel

Abstract AISI 9840 is a nickel-chromium-molybdenum steel very similar to AISI 4340 with lower nickel and slightly higher manganese. In the heat treated condition it has good combination of strength, fatigue resistance, toughness and wear resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-55. Producer or source: Alloy steel mills and foundries.

Effect of Electrolyte Composition on Corrosion Resistance in Nickel Plating Process for Coating Bonded Magnet PrFeB

2014 ◽  
Vol 896 ◽  
pp. 245-248 ◽  
Author(s):  
Candra Kurniawan ◽  
Hayati M.A. Sholihat ◽  
Kemas Ahmad Zaini Thosin ◽  
Muljadi ◽  
Prijo Sardjono
Keyword(s):  
Magnetic Properties ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Nickel Coating ◽  
Electrolyte Composition ◽  
Nickel Metal ◽  
Sem Images ◽  
Average Value ◽  
Immersion Corrosion ◽  
Bonded Magnet

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.

scholarly journals Protection of Aluminum Foils against Environmental Corrosion with Graphene-Based Coatings

2021 ◽  
Vol 8 ◽  
pp. 18-28
Author(s):  
George Paterakis ◽  
George Anagnostopoulos ◽  
Labrini Sygellou ◽  
Costas Galiotis ◽  
◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Sulfuric Acid ◽  
Inhibition Efficiency ◽  
Lithium Perchlorate ◽  
Aluminum Foil ◽  
Corrosion Performance ◽  
Acidic Conditions ◽  
Corrosion Inhibition Efficiency ◽  
Commercial Applications ◽  
Lower Corrosion Rate

Commercial aluminum foils were coated by graphene oxide, and its functionalized derivatives and the corrosion performance of the coated specimens were examined in acidic conditions (lithium perchlorate and sulfuric acid). Electrochemical experiments have shown that all graphene oxide-coated specimens provided up to 96% corrosion inhibition efficiency with a corresponding lower corrosion rate compared to the bare aluminum foil. Our results clearly show that graphene-related materials offer viable alternatives for the protection of aluminum, and this opens up a number of possibilities for its use in a number of commercial applications.

scholarly journals Effect of Heat Treatment and Sulfuric Acid Anodization on Corrosion Resistance of Aluminum Alloy (AA7075)

2021 ◽  
Vol 40 (1) ◽  
pp. 56-62
Author(s):  
M. Abdullahi ◽  
L.S. Kuburi ◽  
P.T. Zubairu ◽  
U. Jabo ◽  
A.A. Yahaya ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Polarization Resistance ◽  
Testing Machine ◽  
Palm Kernel ◽  
Engine Oil ◽  
Micro Hardness

This paper, studied the effect of heat treatment and anodization on corrosion resistance of aluminum alloy 7075 (AA7075), with a view to improving its corrosion resistance. Microstructure and micro hardness of the anodic film of the samples were studied with the aid of optical metallurgical microscope and automated micro hardness testing machine. Linear polarization methods were used to assess the corrosion behaviour of the alloy in 0.5M HCl. The microstructure of the annealed sample showed formation of dendrites while precipitation hardened samples in palm kernel oil and SAE 40 engine oil showed precipitates of MgZn2. The SEMS result showed pores and micro cracks on the surfaces of the anodized samples, with the as cast and anodized sample in sulfuric acid exhibiting most compact with few pores. The as cast and sulfuric acid anodized sample shows highest micro hardness value of 205.33 HV, while the least value of 150.67 HV was recorded in sample precipitation hardened in SAE 40 engine oil and anodized in sulfuric acid. Analysis of the potentiodynamic polarization data and curves showed a linear relationship (decrease in icorr, decreases the corrosion rate) between current density and the corrosion rate in all the samples. Higher polarization resistance of 15.093 Ω/cm2 was recorded by the as cast and Sulfuric acid (SA) anodized sample while the precipitation treated in SAE 40 engine oil plus SA anodized sample recorded lowest polarization resistance of 5.2311 Ω/cm2. Heat treatment alone improves corrosion resistance of AA 7075 in 0.5 M HCl solution but heat treatment plus SA anodization does not improve corrosion resistance in the same environment.

scholarly journals Evaluation of the Corrosion Resistance of WC-Co Coating on AZ91 Applied by Electro Spark Deposition

2020 ◽  
Vol 20 (1) ◽  
pp. 30-40
Author(s):  
Arvin Taghizadeh Tabrizi ◽  
Maryam Pouzesh ◽  
Farhad Farhang Laleh ◽  
Hossein Aghajani
Keyword(s):  
Corrosion Rate ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Bulk Sample ◽  
Az91 Alloy ◽  
Corrosion Performance ◽  
Surface Microhardness ◽  
Optimum Parameters ◽  
Temperature Polarization ◽  
First Time

Abstract In order to enhance the surface properties of a magnesium-based substrate, WC-Co coating was applied on AZ91 alloy by electro spark deposition (ESD), successfully for the first time. The optimum parameters of the ESD process were achieved, based on the corrosion behavior and calculated corrosion rate of the coated samples when 5kHz and 25 A were chosen. For evaluation of the corrosion performance of the achieved WC-Co layers, polarization, and electrochemical impedance spectroscopy tests were carried out in the 3.5 wt % Na3PO4 solution at room temperature. Polarization results show that the corrosion rate (mpy) is in the optimum condition almost half of a bulk sample of uncoated AZ91. Field emission scanning electron microscopy (FE-SEM) was used to examine the surface morphology of applied coatings. These results show that at a lower current, the amount of deposited WC-Co was reduced. The maximum surface microhardness obtained was 193 HV0.2.

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