scholarly journals Strong and ductile Fe-24Mn-3Cr alloy resistant against erosion-corrosion

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yeong Jae Jeong ◽  
Si On Kim ◽  
Jin Sung Park ◽  
Jae Won Lee ◽  
Joong-Ki Hwang ◽  
...  
Keyword(s):  
Electrochemical Corrosion ◽  
High Strength ◽  
Environmental Stability ◽  
Ferrous Alloys ◽  
Synergistic Interactions ◽  
Erosion Corrosion ◽  
Environmental Instability ◽  
Superior Mechanical Properties ◽  
Bearing Alloy ◽  
Corrosive Environments

AbstractThe ternary-based Fe-24Mn-3Cr alloy has superior mechanical properties based on an attractive combination of high strength and ductility, with long-term environmental stability in highly corrosive environments compared to conventional ferritic steel alloys. This study reports that the environmental instability caused by the rapid electrochemical corrosion kinetics on the surface of conventional high Mn-bearing ferrous alloys could be overcome by a combination of high Mn–low Cr-balanced Fe and their synergistic interactions. In contrast to Cr-free Mn-bearing alloys, the high Mn–low Cr-bearing alloy showed comparatively lower corrosion kinetic parameters, without a continuously increasing trend, and higher polarization resistance according to electrochemical polarization and impedance spectroscopy measurements. Moreover, the rate of degradation caused by erosion–corrosion synergistic interaction under erosion–corrosion dynamic flow conditions was the lowest in the high Mn–low Cr-bearing alloy. These surface-inhibiting characteristics of the alloy were attributed primarily to the formation of a bilayer scale structure consisting of inner α-Fe2−xCrxO3/outer FexMn3−xO4 on the surface.

Exploitation Load Impact on Electrochemical Properties of Shipbuilding 7xxx Series Aluminum Alloy Joints Prepared with TIG and FSW Methods

2015 ◽  
Vol 236 ◽  
pp. 53-61
Author(s):  
Wojciech Jurczak
Keyword(s):  
Mechanical Properties ◽  
Corrosion Potential ◽  
Tensile Load ◽  
Electrochemical Corrosion ◽  
High Strength ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Superior Mechanical Properties ◽  
Series Aluminum Alloy ◽  
Joint Quality

The paper presents the results of investigations on mechanical properties and electrochemical potential distribution within arc welded (TIG) and friction stir welded (FSW) joints subjected to slow strain rate tests. The materials investigated were high-strength 7xxx series (7020 and its modification 7020M) aluminum alloys intended for shipbuilding. The objectives were joint quality assessment and comparison of the advantages of new FSW method with the traditional TIG methods commonly utilized in shipbuilding industry. Joint quality was evaluated based on mechanical investigations, hardness distribution tests and simultaneous electrochemical corrosion potential measurements at various locations within the welded joints.Initiation of corrosion processes on TIG and FSW joints was identified as a radical decrease in corrosion potential related to load followed by oxide layer cracking. Arc welded (TIG) joints of 7xxx series alloys undergo corrosion at lower values of tensile load applied as compared to the FSW joints. Superior mechanical properties and higher corrosion resistance of the FSW joints make this technology well-suited for joining high-strength 7xxx series alloys.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

MUELLER ALLOY 6741

Alloy Digest ◽  
1971 ◽  
Vol 20 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Wear Characteristics ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Bearing Alloy

Abstract MUELLER ALLOY No. 6741 (formerly 600 Alloy) is a high-strength bearing alloy intended for use in applications requiring a combination of outstanding wear characteristics and high bearing strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-235. Producer or source: Mueller Brass Company.

scholarly journals Electrochemical Corrosion of Ultra-high Strength Carbon Steel in Alkaline Brines Containing Hydrogen Sulfide

2016 ◽  
Vol 212 ◽  
pp. 998-1009 ◽  
Author(s):  
Ruishu Feng ◽  
Justin Beck ◽  
Margaret Ziomek-Moroz ◽  
Serguei N. Lvov
Keyword(s):  
Hydrogen Sulfide ◽  
Carbon Steel ◽  
Electrochemical Corrosion ◽  
High Strength

Computational Model of Mechano-Electrochemical Effect of Aluminum Alloys Corrosion

2021 ◽  
Author(s):  
Hessein Ali ◽  
Zachary Stein ◽  
Quentin Fouliard ◽  
Hossein Ebrahimi ◽  
Peter Warren ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Stress Corrosion ◽  
High Strength ◽  
Critical Issue ◽  
Localized Corrosion ◽  
Multiphysics Coupling ◽  
Electrochemical Effect ◽  
Corrosive Environments ◽  
Elastic And Plastic Deformation ◽  
Kinetics Of

Abstract Stress corrosion is a critical issue that leads to high costs in lost equipment and maintenance, affecting the operation and safety of aircraft platforms. Most aerospace structural components use the aluminum alloys 7xxx series, which contain Al, Cu, Zn, and Mg, due to the combined advantage of its high-strength and lightweight. However, such alloys, specifically AA7075-T4 and AA7075-T651, are susceptible to stress corrosion cracking (SCC) when exposed to both mechanical stresses and corrosive environments. SCC gives rise to a major technological challenge affecting aerospace systems as it leads to the degradation of mechanical properties. In addition, such corrosion presents an important yet complex modeling challenge due to the synergistic action of sustained tensile stresses and an aggressive environment. In light of this, we develop a finite element (FE) multiphysics model to investigate the interplay of mechanical loading and electrochemistry on the stress corrosion of aluminum alloys. The model includes a multiphysics coupling technique through which the kinetics of corrosion can be predicted in the presence of elastic and plastic deformation modes. The presented model provides useful information towards the kinetics of corrosion via tracking localized corrosion and stress distribution. Although the model is general, it has been made considering the characteristics of AA7xxx series, more specifically, taking AA7075.

scholarly journals Simulation Analysis of Erosion–Corrosion Behaviors of Elbow under Gas-Solid Two-Phase Flow Conditions

Lubricants ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 92
Author(s):  
Qunfeng Zeng ◽  
Wenchuang Qi
Keyword(s):  
Chemical Reaction ◽  
Simulation Analysis ◽  
Electrochemical Corrosion ◽  
Simulation Software ◽  
Solid Particles ◽  
Two Phase ◽  
Particle Count ◽  
Coal Gas ◽  
Erosion Corrosion ◽  
Corrosion Behaviors

In the production and gathering process of coal gas, the complex composition of the coal gas, harsh environments, the complex medium, and high content of solid particles in slurry cause the equipment malfunctions and even failure because of erosion and corrosion. In the present study, COMSOL multi-physics finite element simulation software is used to simulate the erosion–corrosion behaviors of elbow in key chemical equipments. The electrochemical corrosion, solid particle erosion, chemical reaction, and turbulent flow are coupled together. The particle count method is proposed to clarify the erosion phenomenon. The simulation results show that particles with high turbulent intensity hit the wall of elbow directly, which forms a slanted elliptical erosion zone on the extrados surface at 40°–50°. The chemical reaction in turbulence has a difference in the concentration distribution of substances, and this phenomenon leads to different magnitudes of the corrosion current densities in the tube. Moreover, 1/6 released particles hit the extrados surface of the elbow. These findings are beneficial to understand the erosion–corrosion phenomena and design the elbow in key chemical equipment.

scholarly journals Complementary Use of APFIM and TEM for a Study of Precipitation in a Rapidly Solidified Stainless Steel

1997 ◽  
Vol 3 (S2) ◽  
pp. 683-684
Author(s):  
T. F. Kelly ◽  
S. Wisutmethangoon ◽  
P. P. Camus ◽  
D. J. Larson ◽  
M. K. Miller
Keyword(s):  
Stainless Steels ◽  
Hot Extrusion ◽  
High Strength ◽  
Dark Field ◽  
Environmental Stability ◽  
Gas Atomization ◽  
Fringe Contrast ◽  
Dark Field Imaging ◽  
Wide Range ◽  
Field Imaging

Stainless steels are important technologically for a wide range of applications. Though they are attractive for their environmental stability, austenitic versions of these steels are not generally known for their very high strength. We have rapid-solidification-processed many stainless steels by gas atomization and achieved strength improvements of over 50% relative to conventionally-processed stainless steels with concomitant improvement in corrosion and oxidation behavior. These strength improvements are most pronounced when elevated concentrations of oxygen and vanadium are present in the metal and we need to know how these elements affect precipitation in the alloy.The specimen material (FCC Fe-16%Ni-9%Cr-0.5%Mn-0.2%V-0.0137%N-0.008%O by weight) was prepared by gas atomization and hot extrusion followed by precipitation aging as described elsewhere. We observed the structure in TEM and found 20 nm precipitates on dislocations, Fig. 1a. We did not observe smaller precipitates in the grain interiors using diffraction contrast bright field imaging, however, with weak-beam dark field imaging, Moiré fringe contrast is observed throughout the material, Fig. 1b.

Efficient Prediction of Contact Behavior in a 6-High Rolling Mill With Continuously Variable Crown Intermediate Rolls

2017 ◽  
Author(s):  
Feng Zhang ◽  
Arif S. Malik
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Mixed Finite Element ◽  
Mixed Finite Element Method ◽  
High Strength ◽  
Computational Time ◽  
Ferrous Alloys ◽  
Thickness Profile ◽  
Wide Range ◽  
Contact Force Distribution

Continuously Variable Crown (CVC) shifting mechanisms represent a control technology with wide range of capability to influence the thickness profile and flatness (shape) of metal strip and sheet in rolling-type manufacturing processes. Further, because of the efficiency and extensive control capability to operate on thin-gauge, high-strength ferrous alloys, the 6-high mill with CVC profiles machined onto the intermediate rolls (IR) represents a popular mill configuration. This is because of the large control range for the strip thickness profile and flatness, which results from lateral shifting of the CVC intermediate rolls. However, together with this efficiency and capability comes very complex contact behaviors between the rolls and strip, including highly non-linear contact force distribution, loss of contact, asymmetric roll wear, unwanted strip wedge profiles, and the need to apply corrective roll tilting. Therefore, for most effective industry use of 6-high mills with intermediate roll CVC shifting, a rapid and accurate mathematical rolling model is needed to predict and account for these complex contact behaviors. This paper introduces an efficient roll-stack computational model capable of simulating such rolling mills under steady-state conditions. The model formulation applies the simplified mixed finite element method (SM-FEM), which is adapted to simulate asymmetric 6-high CVC mill contact behaviors. Results for a specific case study compare favorably to those obtained from a large-scale commercial finite element simulation, yet require a small fraction of the associated computational time and effort.

Nanocrystalline LPSO Mg-Zn-Y-Al Alloys with High Mechanical Strength and Corrosion Resistance

2010 ◽  
Vol 638-642 ◽  
pp. 1476-1481 ◽  
Author(s):  
Hitoshi Okouchi ◽  
Yoshikazu Seki ◽  
Takahiro Sekigawa ◽  
Hirohito Hira ◽  
Yoshihito Kawamura
Keyword(s):  
Corrosion Resistance ◽  
Fatigue Strength ◽  
Yield Strength ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Alloy Development ◽  
High Mechanical Strength ◽  
Lpso Structure ◽  
Superior Mechanical Properties ◽  
Rapidly Solidified

Interests in magnesium alloys increase as eco-material for its lightweight, and many investigations have been carried out on the development of manufacturing processes and alloy development. In 2001, Mg97Zn1Y2 (at%) alloy with a tensile yield strength of 610 MPa and an elongation of more than 5 % has been developed by rapidly solidified powder metallurgy (RS P/M) processing. The developed alloy was characterized by a novel phase with long period stacking ordered (LPSO) structure. Recently, we have investigated new compositions for LPSO RS P/M Mg-Zn-Y-X alloys in order to improve the corrosion resistance of the RS P/M Mg97Zn1Y2 alloy with maintaining the superior mechanical properties. Consequently, we have developed a RS P/M Mg96.7Zn0.85Y2Al0.45 alloy with high strength and high corrosion resistance. The RS P/M Mg96.7Zn0.85Y2Al0.45 alloy contained the LPSO phase and exhibited a tensile strength of 525 MPa, an elongation of 9 % and a fatigue strength of 325 MPa, which were similar to those of the RS P/M Mg97Zn1Y2 alloy. However, the corrosion resistance of the RS P/M Mg96.7Zn0.85Y2Al0.45 alloy was 1.5 times that of the RS P/M Mg97Zn1Y2 alloy. The specific tensile yield strength, the specific fatigue strength and the corrosion resistance of the RS P/M Mg96.7Zn0.85Y2Al0.45 alloy were about 1.7 times, 1.8 times, and twice those of extra-super-duralumin (7075-T6 or 7075-T73), respectively.

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