Evaluation Of Corrosion Resistance Research Articles

Microstructure Evolution and Corrosion Resistance Evaluation of 17-4 Precipitation Hardening Stainless Steel Processed by Laser Powder Bed Fusion

Microstructure Evolution and Corrosion Resistance Evaluation of 17-4 Precipitation Hardening Stainless Steel Processed by Laser Powder Bed Fusion

Experimental Investigation of the Impact of Niobium Additions on the Structural Characteristics and Properties of Ti-5Cr-xNb Alloys for Biomedical Applications.

In this study, a series of Ti-5Cr-xNb alloys with varying Nb content (ranging from 1 to 40 wt.%) were investigated to assess their suitability as implant materials. Comprehensive analyses were conducted, including phase analysis, microscopy examination, mechanical testing, and corrosion resistance evaluation. The results revealed significant structural alterations attributed to Nb addition, notably suppressing the formation of the ω phase and transitioning from α' + β + ω to single β phase structures. Moreover, the incorporation of Nb markedly improved the alloys' plastic deformation ability and reduced their elastic modulus. In particular, the Ti-5Cr-25Nb alloy demonstrated high values in corrosion potential and polarization resistance, signifying exceptional corrosion resistance. This alloy also displayed high bending strength (approximately 1500 MPa), a low elastic modulus (approximately 80 GPa), and outstanding elastic recovery and plastic deformation capabilities. These aggregate outcomes indicate the promising potential of the β-phase Ti-5Cr-25Nb alloy for applications in orthopedic and dental implants.

Electrochemical Corrosion Resistance Evaluation of Zn–Ni Alloy Electroplating Process in Zincate Bath

Electrochemical Corrosion Resistance Evaluation of Zn–Ni Alloy Electroplating Process in Zincate Bath

Addition of molybdate ions to the anodizing bath to improve the corrosion resistance of clad 2024-T3 alloy anodized in tartaric-sulfuric acid

In the present investigation molybdates ions (MoO4−2) were added to a tartaric‑sulfuric acid (TSA) bath, which was employed to anodize AA2024-T3 clad samples. The incorporation of Mo into the anodized layer was investigated by different techniques: X-ray photoelectron spectroscopy (XPS), glow-discharge optical emission spectroscopy (GDOES), Rutherford backscattering spectrometry (RBS) and scanning electron microscopy (SEM), while the corrosion resistance was evaluated by electrochemical impedance spectroscopy (EIS) techniques in neutral (0.5 M) and acidic (0.1 M, pH = 4.0) NaCl solutions. The different characterization techniques indicate that small amounts of the modifier were incorporated into the anodized layer, while the SEM analysis confirmed that the morphology of the layer was not changed, although it was thicker when anodized in the Mo containing bath. Evaluation of corrosion resistance by EIS in both media showed that samples anodized in the molybdate containing bath were more corrosion resistant and durable. Fitting results of the electric equivalent circuit indicate that this may be a consequence of a thicker barrier layer for these samples.

Chemical Interaction between the Sr4Al6O12SO4 Ceramic Substrate and Al–Si Alloys

Samples of Sr4Al6O12SO4 are obtained through a solid-state reaction of Al2O3, SrSO4, and SrCO3. The samples are then made into 1 and 4 cm pellets by compacting them at 100MPa and sintering them at 1400 °C for 4 h. The compound is analyzed using X-ray diffraction. Static immersion and wettability tests are carried out to evaluate corrosion resistance in contact with Al–Si. Corrosion tests are conducted by immersing the samples at 800, 900, and 1000 °C for 24, 50, and 100 h, while wettability is studied at 900, 1000, and 1100 °C for 2 h. Afterwards, the samples are subject to metallographic preparation. The samples are then analyzed using optical microscopy, scanning electron microscopy, and image analysis. In general, reaction products consisting of alumina, spinel, oxides, and sulfates are found. The contact angles obtained are between 124° and 135°. It is concluded that the Sr4Al6O12SO4 ceramic substrate is resistant to corrosion by the Al–Si alloy because of the slight thickness of the reaction products found in the samples (73 μm), considering the severe conditions of the experiment: 1000 °C and 100 h of isothermal temperature. Furthermore, Sr4Al6O12SO4 is not wettable by Al–Si alloys. These results suggest that the ceramic substrate could be used in the refractory industry, possibly as an additive to commercial refractory ceramics. For future work, it is recommended to carry out the same study with the aluminum–magnesium alloy and as an additive in commercial refractory ceramics.

Hardening and improving the corrosion resistance of carbon steel 45 with thermal chemical treatment

The issues of creating a hardening coating by plasma spraying of Ti powder on steel grade 45 with subsequent cementation are considered in order to improve mechanical properties and evaluate corrosion resistance. X-ray phase analysis showed the presence of basic (Fe) and strengthening phases (TiC, Fe3C) in the material under study.

Methods for evaluation of corrosion rate on magnesium alloys: a review

The major drawback of some magnesium alloys is their low corrosion resistance. Therefore, the evaluation of corrosion resistance is a critical factor in developing new alloys and surface treatments. The techniques employed for the determination of corrosion rate include mass loss assessment, hydrogen evolution, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). However, there are still difficulties in precisely estimating this parameter in Mg alloys. In this review, the reported applications, advantages, and disadvantages of the techniques mentioned above were analyzed. On the other hand, a large number of corrosion rate values reported for various Mg alloys in 3 different media (NaCl, Hanks´ solution and SBF), using mass loss, hydrogen evolution, and PP, were compared and analyzed. Generally, corrosion rates obtained from mass loss are higher than those obtained from hydrogen evolution. On the other hand, it is not possible to obtain correlations between corrosion rates obtained from PP and those obtained from mass loss and hydrogen evolution. Even more, dissimilar corrosion rate values are reported for the same alloy, implying that the measuring procedures are not well standardized.

Experimental corrosion resistance evaluation of Cr–Mo-Mn steel surface modified with titanium and nitrogen ions

Experimental corrosion resistance evaluation of Cr–Mo-Mn steel surface modified with titanium and nitrogen ions

Corrosion resistance and other utility properties of selected austenitic nodular cast irons

This study deals with the evaluation of corrosion resistance and other utility properties of selected austenitic nodular cast irons and their comparison with other (non-austenitic) nodular cast irons. For the investigations, two types of austenitic nodular cast iron were selected: nickel-manganese nodular cast iron EN-GJSA-XNiMn13-7 and nickel-chromium nodular cast iron EN-GJSA-XNiCr20-2. Basic mechanical properties, such as yield strength, tensile strength, elongation, absorbed energy and hardness, were evaluated using mechanical tests. The fatigue limit was determined using low-frequency fatigue tests. Corrosion properties, such as average corrosion rate, corrosion potential and corrosion current density, were determined by the exposure immersion test and the electrochemical potentiodynamic polarisation test. Both corrosion tests were performed in a 3.5% NaCl solution (to simulate seawater) at room temperature. The results of mechanical, fatigue and corrosion tests show that austenitic nodular cast irons have lower strength and fatigue properties but significantly higher plastic properties and corrosion resistance compared to non-austenitic nodular cast irons.

Combined severe plastic deformation processing of commercial purity titanium enables superior fatigue resistance for next generation implants

Commercial purity titanium (cp-Ti) is considered for replacing Ti64 as an implant material in various applications, due to the potential toxicity associated with the release of Al and V ions. However, the mechanical properties of cp-Ti, particularly fatigue resistance, are inadequate for this purpose. In this study, cp-Ti grade 4 rods were processed using a combination of equal channel angular pressing and rotary swaging (ECAP/RS). Tensile and fatigue tests were conducted, along with detailed microscopy and evaluation of corrosion resistance and biocompatibility. An average yield strength of 1383 MPa was obtained while maintaining moderate ductility of 10 %. This represents the highest strength ever recorded for cp-Ti, even exceeding that of Ti64. Additionally, fatigue endurance limit increased by 43 % up to 600 MPa, almost obtaining that of Ti64. Strengthening mechanisms were attributed to the ultrafine-grained (UFG) microstructure generated by ECAP/RS, along with strong crystallographic texture and formation of sub-grain structure. Furthermore, the corrosion resistance and biocompatibility of cp-Ti were largely unaffected, potentially easing regulatory transition in future medical devices. Thus, these results demonstrate high potential of combined ECAP/RS processing to manufacture UFG cp-Ti grade 4 materials that prospectively allow for the substitution of questionable alloys and downsizing of medical implants.

Eco-friendly approach for the fabrication of biо copper based superhydrophobic coating on steel metal and its corrosion resistance evaluation

This study presents an eco-friendly approach for constructing superhydrophobic (S.H.) coatings on steel surfaces. The biо Сu nanoparticles are synthesized using a biоgenic process. Two types of coatings, Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α, were developed and characterized. The EDX results confirm the successful fabrication of two distinct coatings on the steel substrate: one involving the modification of nickel with stearic acid, Ni-Ѕ.Α, and the other involving the modification of nickel with both bio-Cu and stearic acid, Ni-biо Сu-Ѕ.Α. The SEM results revealed that the S.H. coats exhibit circular microstructures which contribute to the surface roughness. The contact angles of water droplets on the Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α coatings were measured at 158° ± 0.9° and 162° ± 1.1°, respectively. Chemical stability tests demonstrated that the Ni-Ѕ.Α coating maintains its S.H. behaviour in a pH range of 3–11, whereas the Ni-biо Сu-Ѕ.Α coating exhibits excellent chemical stability in a broader range of pH (1-13). The coating's mechanical stability was evaluated through abrasion tests. The Ni-Ѕ.Α coating retained its S.H. properties even after an abrasion length equal 1100 mm, while the Ni-biо Сu-Ѕ.Α coating maintained its S.H. behaviour till an abrasion length equal 1900 mm. The corrosion behavior and protective properties of the S.H. coatings were studied via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The PDP and EIS findings demonstrated that both Ni-Ѕ.Α and Ni-biо Сu-Ѕ.Α coatings significantly reduced the corrosion rate compared to uncoated steel.

Al-induced electroless Co/Sn bi-layered deposition and evaluation of corrosion resistance

Al-induced electroless Co/Sn bi-layered deposition and evaluation of corrosion resistance

Rapid chloride penetration test: An evaluation of corrosion resistance in ultra-high performance concrete

Six Ultra-High Performance Concrete (UHPC) mixtures were tested to determine their chloride ion ingress potential using the rapid chloride penetration test (RCPT). The UHPC mixtures showed low to negligible chloride ion penetrability, depending on their water to cementitious materials (w/cm) ratio and curing regimen. Electrical resistivity and conductivity of the mixtures were determined based on the recorded electric current during the RCPT test. The electrical resistivity varied from 49 to 1419 Ω-meter, while conductivity ranged from 0.0007 to 0.0013 milli-Siemens/meter, indicating a moderate to very low expected corrosion rate for the mixtures. The chloride diffusion coefficient was calculated using the Nernst-Plank Equation, making corrections for Joule effect and temperature adjustment due to the temperature increase of the electrode solution during the RCPT test. The chloride ion diffusion coefficients of the UHPC mixtures ranged from 0.53–3.01 × 10−15 m2/s. These results suggest that UHPC mixtures with a w/cm ratio as high as 0.30 can exhibit excellent corrosion resistance.

Evaluation of Mechanical Properties, Corrosion Resistance, and Pore Structure of Stepwise PCM Aggregate Concrete

Stepwise phase change material (PCM) aggregate concrete has advantages in controlling temperature and resisting frost heave, but its freeze–thaw resistance performance is still unclear. This paper explored the impact of replacing ordinary coarse aggregate with stepwise aggregate on the freeze–thaw resistance characteristics of concrete. Firstly, the compressive strength, splitting tensile strength, and their relationship were evaluated. Then, the freeze–thaw resistance properties of PCM aggregate concrete were investigated, including macroscopic changes, mass loss, relative dynamic elasticity modulus loss, and compressive strength loss. Subsequently, the pore changes before and after freeze–thaw cycles were tested through non-destructive testing and nuclear magnetic resonance (NMR) testing, and the evolution of pores under freeze–thaw cycles was explored. The results show that adding 100% PCM aggregate reduces the strength of concrete by 32%. However, due to the high porosity in the 100% PCM aggregate concrete, it would have an adverse impact on corrosion resistance. The corrosion resistance of concrete increases firstly and then decreases with the addition of PCM aggregate, which can be attributed to PCM aggregate having a limiting effect on pore development. Overall, a substitution rate of 60% is acceptable for compressive strength and corrosion resistance.

Evaluation of Corrosion Resistance of GTAW API 5L X60 Steel / 2205 Duplex Stainless Steel Dissimilar Welds Produced with Different Heat Inputs.

Evaluation of Corrosion Resistance of GTAW API 5L X60 Steel / 2205 Duplex Stainless Steel Dissimilar Welds Produced with Different Heat Inputs.

Coconut coir dust extract as a novel green corrosion inhibitor for carbon steel in the chloride-contaminated concrete pore solution

The potential of coconut coir dust to inhibit corrosion, especially the pitting of rebars in concrete was tapped by electrochemical techniques. Electrochemical impedance spectroscopy and linear polarization results show that both deionized water and ethanol extracts of coconut coir dust can slow down corrosion development by forming a protective film even after long-term exposure to chloride and the latter performs better and is more stable. Cyclic potentiodynamic polarization results further show that ethanol extract at a concentration of 0.1 g/L can significantly delay the initiation of pitting. This inhibitor has exhibited the highest inhibition efficiency, which can be sustained at over 90 % even after six months of immersion in solutions with high chloride concentration, but increasing the concentration of the inhibitor does not result in any additional improvement in its efficiency. Critical chloride concentration for corrosion initiation prediction and corrosion resistance evaluation was also discussed.

Development and Evaluation of Corrosion Resistance and Hydrophobic Properties of Thermal Sprayed Coatings over Carbon Steel

Various industrial parts and equipment made of steel need to withstand demanding conditions. In order to increase performance and lifetime, surface processing and functional coatings can be applied. In this study we report on the evaluation of coated carbon steel with commercial corrosion-resistant powders Diamalloy 4276 and Woka 7502 by Oerlikon Metco, using thermal spraying. Further functionalization is performed by rendering thermal sprayed surfaces syperhydrophobic via gas phase deposition of trichloro-1H,1H,2H,2H-perfluorooctyl silane, (PFOTS). Electrochemical impedance spectroscopy, contact angle and water condensation studies reveal the protective properties of coatings prepared by both materials as well as the superiority of Diamalloy 4276 based coatings. Corrosion was evaluated under a harsh 20% w/w H2SO4 environment. Rendering the coating superhydrophobic improves water condensation under the tested conditions of high (80%) relative humidity.

Evaluation of Corrosion Resistance and Passive Film Properties of Industrial Chromium Plating by Immersion Potential Monitoring

Evaluation of Corrosion Resistance and Passive Film Properties of Industrial Chromium Plating by Immersion Potential Monitoring

Evaluation of corrosion resistance of marine engineering materials under function integral algorithm

Abstract Significant corrosion problems in materials related to marine engineering projects are bound to be a threat to overall operational safety and reliability. This paper investigates the influence of corrosion time on the material product film performance and its corrosion resistance, combined with the function integral algorithm. The gray matrix transform, image binarization, and wavelet transform of the function integral algorithm are used to establish the corrosion damage image recognition model and quantify the microscopic characteristics of corrosion damage based on the corrosion morphological features. Through the corrosion damage image recognition model, evaluation and analysis of common marine engineering materials 2205 duplex stainless steel and Q420 steel in chloride ion (Cl−). Test results show that: chloride ion on 2205 duplex stainless steel corrosion resistance 17.89μA cm−2 was the critical point, the higher the concentration played a suppressive effect. Chloride ions on Q420 steel corrosion resistance in lower solutions below 2.23μA cm−2 concentration, Q420 surface product film has a certain protective effect on the substrate. The corrosion characteristic value evaluation results based on the function integration algorithm are consistent with the electrochemical test results, so the evaluation model established in this paper can effectively evaluate the corrosion resistance of the material.

Evaluation of corrosion resistance of 316L stainless steel by laser ultrasonic nondestructive testing technology

At present, the corrosion resistance of materials such as 316L stainless steel is mainly tested by electrochemical testing, which is time-consuming, laborious and environmentally unfriendly. In this paper, the laser ultrasonic detection technology, which is a rapid, non-destructive, pollution-free microstructure and corrosion resistance evaluation method is used for the detection of 316L stainless steel, and the ultrasonic signals are filtered by the wavelet threshold denoising method. The results show that the laser ultrasonic attenuation coefficient obtained by the wavelet threshold denoising signal processing method has a good correlation with the corrosion resistance of 316L stainless steel. A laser ultrasonic potential evaluation model was established based on the passivation film rupture potential and ultrasonic attenuation coefficient. The average relative error of the evaluation model for corrosion resistance of 316L stainless steel is less than 5.00%. The relative error of corrosion resistance evaluated by the laser-receiving method is lower than that by the probe-receiving method. It is feasible to nondestructive evaluation of the corrosion resistance of 316L stainless steel by laser ultrasonic technology.