Corrosion Behavior Of Materials Research Articles

Effect of Silver Content on Microstructure and Corrosion Behavior of Material Prepared from Silver Coated Iron Powder

Iron was considered a good material candidate for temporary implants in cardiovascular and orthopedic surgery. Mechanical properties of iron are attractive, however, a higher degradation rate is required. The contribution deals with the effect of silver content on microstructure and corrosion behavior of materials prepared from Ag coated iron powders. Using electroless deposition, Fe-powders with 0.29 and 2.1 wt.% of silver were prepared. Cylindrical specimens compacted at a pressure of 200 MPa were isothermally sintered at 1120°C for 60 min. The microstructure of the sintered specimens consisted of iron matrix with Ag-precipitates. The corrosion behaviour of sintered compacts was studied using the potentiodynamic polarization technique in Hank’s solution and complemented with SEM analysis. It was found out that corrosion resistance of material decreased with an increase in silver content.

Mechanical and corrosion properties of Mg based alloys considered for medical applications as biodegradable materials

Magnesium and its alloys are considered as suitable biodegradable materials which can be gradually dissolved in organism without production of toxic compounds. The present study is oriented on new group of possible biodegradable materials based on Mg-LMM (Mg- low melting metals) alloys. Due to the limited information about the effect of Ga, Sn and In on mechanical and corrosion properties, structure studies, mechanical and corrosion testing were performed. Corrosion behaviour of materials was studied using measuring of weight changes, Mg ions release and also by EIS technique in SBF (simulated body fluid) that is close in composition with human plasma. The obtained results indicate positive effect of both Ga and Sn on tensile and compressive properties, compared to the almost neglectable effect of In. On the contrary, all materials were characterized by decreased corrosion resistances compared to pure Mg. Mainly structure conditions were responsible for observed differences in corrosion rates.

Corrosion of Copper Pipeline Systems under Different Flow Conditions

In the current study, the material corrosion behavior and degradation of a closed-loop copper piping systems were investigated taking temperature and flow parameters into consideration. To simulate the practical environment conditions, two identical copper closed-loop piping systems were constructed with three types of joints. Both systems were filled with 3% sodium chloride solution and run for about eleven months period. They were heated to a temperature of 80°C for eight hours a day and for 5 days a week. Outside that heating period, systems were maintained at room temperature (23± 2°C). Within such a heating interval, the contained solution for one system was kept in stagnation condition while it was flowing at input velocity of 0.27 m/s for the other. For both systems, the corrosion was then assessed and quantified using different evaluation techniques: Potentiodynamic test, Pourbaix diagrams, light microscope and scanning electron microscopy (SEM). The experimental results confirmed a diverse significant influence of solution flowing conditions on the damage of copper pipes.

CORROSION BEHAVIOR OF COPPER ALLOYS IN DEEP OCEAN ENVIRONMENT OF SOUTH CHINA SEA

The corrosion in deep ocean environment has been paied more and more attentions to the exploitation of marine resources.Different from shallow marine environments,deep ocean environments are specially characterized by high hydrostatic pressure,low temperature,variable dissolved oxygen content and pH value in deep ocean,etc..So the corrosion behaviour of materials,such as ferrous and nonferrous metal and coatings,in deep ocean environments is different from that in shallow marine environments.A number of researches have been carried out to investigate the corrosion behaviour of metals in natural deep ocean in a few developed countries.Such researches,however,began until 2008 in South China Sea.In this work,the corrosion behavior of H62 brass,QA19-2 and QSn6.5-0.1 bronze in 800 and 1200 m deep ocean environments of South China Sea was studied using field tests.The results indicated that the corrosion rates of copper alloys decreased in the following order:H62(0.042 mm/a) QSn6.5-0.1(0.004-0.007 mm/a) QA19-2(0.003 mm/a).The corrosion rate of H62 brass decreased linearly with the increase in depth.While the corrosion rates of QA19-2 and QSn6.5-0.1 bronze decreased first and then increased with the increase in depth.The minimum value of corrosion rate occurred between 800-1200 m.The morphology and composition of corrosion products were investigated using SEM,EDS and XRD.The results demonstrated that the dezincification corrosion obeying solution-redeposition mechanism in H62 brass occurred.The corrosion products were composed of Cu,ZnO,Zn_5(OH)_8Cl_2H_2O and Cu(OH)_2H_2O.And the dealloying corrosion in QA19-2 and QSn6.5-0.1 bronze occurred.The corrosion products of QA19-2 bronze consistof Cu_2O and CuCl_2,and those of QSn6.5-0.1 bronze Cu_2O,CuCl_2 and Cu_2Cl(OH)_3.

The influence of copper in ash deposits on the corrosion of boiler tube alloys for waste‐to‐energy plants

Previous laboratory studies reported in the literature and field experience have revealed the accelerating effect of the heavy metals lead and zinc on the corrosion behaviour of materials used in waste incineration plants. The major problem is that heavy metal containing chloride and sulphate salts usually have relatively low melting points, often below the metal temperature of the boiler surfaces. While the negative influence of lead and zinc is well‐known, copper is another heavy metal that can occur in high amounts of up to 2000 mg/kg in refuse‐derived fuel, which is the fuel produced by shredding and dehydrating solid municipal waste that is burned in modern waste‐to‐energy plants. The impact of copper additions on the corrosion behaviour of one iron‐based austenitic alloy 1.4952 and three nickel‐based alloys 2.4856 (alloy 625), 2.4633 (alloy 602 CA), 2.4605 (alloy 59), which are often used in waste incineration plants was investigated. The results of these studies clearly show the strong corrosive effect of copper content in salt mixtures on the corrosion of steels and nickel‐based alloys.

Grain size distribution effects on the corrosion behaviour of materials

While the effect of grain size refinement on the corrosion behaviour of materials is well studied, the effect of grain size distribution has not been explored. By utilising existing correlations between corrosion current and grain size, we derive relationships for corrosion current and grain size distribution. These relationships suggest that for the same average grain size, a broader grain size distribution leads to increased corrosion resistance in a non-passivating environment and vice versa in a passivating environment. These relationships are also used to predict the corrosion behaviour of bimodal microstructures.

Materials and Corrosion Research in the Yucca Mountain Project

There is a current nuclear energy renaissance around the world, mainly in Asia. However, after 60 years of using nuclear power, the issue of nuclear waste still needs to be solved. All the countries currently addressing the issue of nuclear wastes are considering disposing them in stable geologic formations. Most repositories designs in Europe are considering materials such as carbon steel and copper for the container. The US repository in Yucca Mountain is currently on hold waiting for new recommendations from the Blue Ribbon Commission. A robust corrosion and materials testing program was carried out over the last 20 years at universities and National Laboratories to support the Yucca Mountain Project. For example, the intensive corrosion and electrochemical research helped understanding of how the different variables affect the resistance of C-22 to localized corrosion. Even if the repository of Yucca Mountain is not materialized, the knowledge gained on the corrosion behavior of materials is permanent.

Corrosion behaviors of materials in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid

The corrosion properties of carbon steel (CS), 304 stainless steel (304 SS), and pure titanium (Ti) are first studied in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid (IL). An active-to-passive transition behavior was clearly observed for CS. The 304 SS exhibited the best stability among the materials; no considerable corrosion was recognized even in this high-chloride environment. In contrast, although Ti resists corrosion in ambient environments, it was not passivated in the IL and became severely corroded under an anodic applied potential. The material corrosion behaviors and mechanisms in the non-aqueous, low-oxygen, and high-halogen-containing IL are completely different from those in traditional aqueous solutions.

In field electrochemical evaluation of carbon steel corrosion in a marine test environment

PurposeThe purpose of this paper is to research electrochemical testing technology as applied to in field corrosion evaluation of metallic materials and to study the corrosion behaviors of the materials exposed in different marine regions.Design/methodology/approachThe electrode systems for in field electrochemical evaluation of metallic samples are designed and applied to monitor two types of carbon steel samples exposed both in the submerged zone and the tidal zone at a marine corrosion test station. Corrosion potential monitoring, potentiostatic square wave, electrochemical impedance spectroscopy, and electrochemical noise methods are used in the test.FindingsIt is confirmed that the electrode systems could be used for electrochemical measurement of metallic samples during exposure in the submerged zone and the tidal zone of a marine corrosion test station for long‐term test durations. The electrochemical measuring results reflect the changes and differences of the samples' corrosion behavior during exposure in different regions and they respond directly to the influence of marine environmental factors on the corrosion behaviors, especially the influence of temperature.Originality/valueIn this paper, lots of consecutive and dynamic corrosion information is obtained from field exposures. The findings provide a foundation upon which to investigate and forecast the corrosion behaviors of materials in marine environments.

Corrosion of the Materials in Sulfuric Acid

A program for a hydrogen production by using a high temperature nuclear heat has been launched in Korea since 2004. Iodine sulfur (IS) process is one of the promising processes for a hydrogen production because it does not generate carbon dioxide and a massive hydrogen production may be possible. However, the highly corrosive environment of the process is a barrier to its application in the industry. Therefore, corrosion behaviors of various materials were evaluated in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Ni based alloys, Fe–Si alloys, Ta, Au, Pt, Zr, SiC, and so on. The test environments were boiling 50 wt % sulfuric acid without/with HI as an impurity and 98 wt % sulfuric acid. The surface morphologies and cross-sectional areas of the corroded materials were examined by using the scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). From the results of the weight loss and potentiodynamic experiments, it was found that a Si enriched oxide is attributable to a corrosion resistance for materials including Si in boiling 98 wt % sulfuric acid. Moreover, the passive Si enriched film thickness increased with the immersion time leading to an enhancement of the corrosion resistance. Corrosion behaviors of the material tested are discussed in terms of the chemical composition of the materials, the corrosion morphology, and the surface layer’s composition.

Electrochemical Corrosion Behavior of Nickel-Coated Carbon Fiber Materials in Various Electrolytic Media

Nickel-coated carbon fiber material is of interest to a number of important industry sectors. The present paper reports a complex study of the corrosion performance of 12K (12,000 single filaments) composite tows. The corrosion behavior of this material was examined in dilute , -based neutral and solutions, with respect to its potential application in electrochemical cathodic protection and bipolar plate (fuel cell) technologies. The composites were produced by electro- (or electroless ) deposition of an ultrathin (ca. ) Ni coating onto Hexcel 12K carbon fiber tow. A commercially available, electrodeposited 12K product (Toho-Tenax fiber) was used as a reference material.

Field analysis and corrosion simulation for the material selection of decoupling elements

Flexible, gas-tight metallic ducts are designed to decouple the movements and vibrations between the vehicle’s combustion engine and its exhaust line. These decouplers have to withstand extremely high operational stresses: With gas temperatures up to 1000 °C, their thin-walled components are exposed to a combination of large deformations and corrosive salt spray attack. As there is only very few literature available on the corrosion behavior of materials under these loads, the company Witzenmann presents a procedure how a material selection can be executed.

The use of neural networks in understanding and predicting oxidation and corrosion behaviour in advanced energy conversion systems

Neural networks can be a useful tool to analyse the oxidation and corrosion behaviour of materials at high temperature. Examples are given of the use of neural network models to analyse datasets of material behaviour after exposure to combustion, gasification and steam atmospheres. The use of networks to identify changes in mechanism, additional significant experimental parameters and the onset of spallation is demonstrated.The limitations of neural network modelling are briefly discussed. Although they can be trained to fit any existing dataset, care must be taken in using the networks to predict a time sequence of events.

The use of neural networks in understanding and predicting oxidation and corrosion behaviour in advanced energy conversion systems

Neural networks can be a useful tool to analyse the oxidation and corrosion behaviour of materials at high temperature. Examples are given of the use of neural network models to analyse datasets of material behaviour after exposure to combustion, gasification and steam atmospheres. The use of networks to identify changes in mechanism, additional significant experimental parameters and the onset of spallation is demonstrated.The limitations of neural network modelling are briefly discussed. Although they can be trained to fit any existing dataset, care must be taken in using the networks to predict a time sequence of events.

Corrosion behavior of materials in RO water containing 250–350 ppm chloride

Reverse osmosis (RO) water constitutes about 22% of total desalinated water produced in the world. The rest of the desalinated water is almost entirely from thermal distillation, such as multistage flash (MSF) evaporation and multi-effect desalination (MED) techniques. The RO permeate is more corrosive than water produced by thermal distillation due to its high dissolved salts (TDS) level, particularly chlorides. As the RO water is transported through cementitious or polymer lined pipelines, steel components like pumps, valves and pipes are likely to corrode, if proper material selection is not made. Not much information is available regarding the corrosion behavior of RO water towards the metallic materials particularly steels which forms the bulk of constructional materials. A study has been conducted to investigate the corrosion behavior of some structural materials which include carbon steel 1018, electroless nickel plated carbon steel 1018 ENP, austenitic stainless steel AISI 304, and martensitic stainless steels AISI 410, AISI 420 and AISI 431 in RO water. These materials have been the main constructional materials used in metallic components of pipelines in Saudi Arabia. Studies have been carried out under dynamic conditions (impingement under flow), static conditions (crevice formers) and in presence of an inhibitor (phosphate) using a dynamic test loop. High chromium steels (>15% Cr) appear to provide good resistance where as low chromium steels (<15% Cr) exhibit generally poor resistance under the above mentioned test conditions.

Prediction of long-term corrosion and mechanical behaviors of steel in seawater by an electrochemically accelerated aging technique

Conventional corrosion testing is a time-consuming and expensive process because it requires months or years of exposure for reliable results. Thus, it is necessary to develop a simple, fast, and accurate corrosion testing method for predicting the long-term corrosion behavior of materials. In this article, the corrosion behavior of a steel specimen equivalent to that of the same specimen exposed to seawater for 90 days was reproduced in a short time (24 h) using an electrochemically accelerated aging, technique. The results indicated that the short-term accelerated aging, test yields good qualitative and quantitative agreement with a long-term immersion test in terms of weight loss, corrosion product, and type of corrosion. Furthermore, based on the experimental results, it was possible to predict the long-term mechanical behavior of the corroded structure. The tensile 1/4 of the initial strengths, respectively.

Effect of ion irradiation and implantation of H and He on the corrosion behavior of austenitic stainless steel

It is important to evaluate the effect of irradiation on the corrosion behavior of materials to be used in spallation neutron sources. Solution annealed high purity Fe–18Cr–12Ni specimens were used in this study. Ni 3+ and H + or He 2+ ions were injected at 473–773 K. After corrosion test, the specimens were examined with atomic force microscope (AFM) to evaluate the corrosion behavior. It was shown that the corrosion rate of the irradiated area increased with increasing dose and temperature. H implantation accelerated corrosion. On the other hand, He implantation seemed to suppress corrosion. Mechanisms for these effects of the different irradiation conditions on the corrosion behavior are discussed.

Susceptibility of Materials to Cavitation erosion in Hong Kong

The authors studied the cavitation erosion and corrosion behaviors of materials—copper, brass, bronze, cast iron, and stainless steel—commonly used in cold water supply systems in Hong Kong. An ultrasonic vibration system was used to estimate the cavitation erosion for both local tap water and deionized water. Polarization technique was used to study the corrosion behavior of materials in tap water; the contributions of mechanical erosion, corrosion, and erosion–corrosion were also investigated. The resistance of these materials to cavitation erosion for local tap water was ranked (in decreasing order of resistance) as follows: stainless steel, brass, bronze, cast iron, and copper. The authors propose, based on their findings, a simple formula for estimating the fractional increase in metal release attributable to cavitation erosion.

Compatibility Test of SiC/SiC Composite Materials and AlN with Liquid Li and Li17Pb83

A purpose of the present study is to investigate the compatibility of SiC/SiC composite material and AlN ceramics with liquid metals. Corrosion behavior of materials could be affected by non-metallic impurities like nitrogen in liquid lithium. Another purpose of the present study is to control the concentration of nitrogen impurity by using getter materials and to study the effect of getter materials on compatibility with AlN. At 700K, all of the SiC/SiC specimens, except high purity specimen, were entirely broken down in liquid lithium. Even in this high purity specimen, many cracks were observed on the surface. On the other hand, in the case of SiC/SiC with Li17Pb83 at 773K, all of the specimens were not corroded. At 673K, impurity levels in AlN were changed in the case immersed in liquid lithium with getter materials. At 823K, impurities in AlN were attacked by lithium and the surface of it was locally peeled off. It was also observed that the getter material captured nitrogen.

Ion implantation for high temperature corrosion protection

Ion implantation has only limited potential as a corrosion protective treatment in high temperature technological applications. Far more important is the indirect contribution of ion implantation to corrosion science as a research tool to study the influence of various elements on the corrosion behaviour of materials. It can be a very efficient technique in the frame of screening tests for evaluating the effect of possible alloying additions in materials. Additionally, it can also play a role to study the underlying corrosion mechanisms. In the present paper this is illustrated with some high temperature corrosion studies. Notably, its use for studying the mechanisms underlying the so-called reactive element effect; for developing more corrosion resistant TiAl-based intermetallic alloys and to address mechanistic questions concerned with mixed oxidation/sulphidation. It is concluded that ion implantation is a powerful tool in high temperature corrosion studies, and can thus be very helpful for material development.