Corrosion Resistance Of Steel Research Articles

A Review of Trends in Corrosion-Resistant Structural Steels Research-From Theoretical Simulation to Data-Driven Directions.

This paper provides a review of models commonly used over the years in the study of microscopic models of material corrosion mechanisms, data mining methods and the corrosion-resistant performance control of structural steels. The virtual process of material corrosion is combined with experimental data to reflect the microscopic mechanism of material corrosion from a nano-scale to macro-scale, respectively. Data mining methods focus on predicting and modeling the corrosion rate and corrosion life of materials. Data-driven control of the corrosion resistance of structural steels is achieved through micro-alloying and organization structure control technology. Corrosion modeling has been used to assess the effects of alloying elements, grain size and organization purity on corrosion resistance, and to determine the contents of alloying elements.

Reinforced corrosion resistance of mild steel in acidic medium by bis(2-acetylpyridine)dithiosemicarbazone (DTSc): electrochemical, surface and spectroscopic studies

Reinforced corrosion resistance of mild steel in acidic medium by bis(2-acetylpyridine)dithiosemicarbazone (DTSc): electrochemical, surface and spectroscopic studies

Electrochemical Corrosion Behavior of Passivated Precipitation Hardening Stainless Steels for Aerospace Applications

Precipitation-hardening (PH) stainless steels (SS) are widely used in various aerospace applications. These steels exhibit good mechanical and corrosion resistance. The electrochemical behavior of 15-5PH, 17-4PH, Custom450 and AM 350 stainless steels passivated with citric and nitric acid baths for 60 and 90 min at 25 and 49 °C were evaluated in 5 wt.% sodium chloride (NaCl) and 1 wt.% sulfuric acid (H2SO4) solutions. The electrochemical behavior was studied with potentiodynamic polarization curves (PPC) according to the ASTM G5-13 standard. The results indicated that there are two characteristic mechanisms that are present in the potentiodynamic polarization curves. When the PHSS is immersed in an H2SO4 solution, there is a secondary passivation, and in the NaCl solution, there is a pseudo-passivation (not stable passivation film). The current densities in the NaCl solution were between 10−4 and 10−5 mA/cm2, while those of H2SO4 were recorded around 10−2 and 10−3 mA/cm2. Citric acid does work as a passivating solution, and in some cases, the corrosion resistance of the stainless steel was comparable to that of nitric acid.

Effect of Ca and Sb on the Corrosion Resistance of E690 Steel in Marine Atmosphere Environment

This study investigates the impact of Ca and Sb elements on the corrosion resistance of E690 steel in a simulated marine environment. Electrochemical testing and dry/wet cyclic corrosion testing were conducted on prepared E690 steel specimens. The eroded specimens’ microstructure was observed under a scanning electron microscope, and the inclusion morphology was analyzed using an energy-dispersive spectrometer (EDS). The simulating liquid was designed to emulate the severe marine atmospheric environment in Xisha. Results showed that the addition of Ca and Sb elements effectively enhances the corrosion resistance of E690 steel in the simulated marine environment. The corrosion rates of E690 steel specimens with Ca and Sb additions were lower than those without, and the corrosion morphology was more uniform. These findings suggest that the addition of Ca and Sb elements can improve the corrosion resistance of E690 steel in simulated marine environments and have potential for use in marine engineering applications.

Passivation Effect of the Chlorinated Paraffin Added in the Cutting Fluid on the Surface Corrosion Resistance of the Stainless Steel.

Cutting fluids are the most effective method to lower the cutting temperature and decrease the cutting tool wear. At the same time, the cutting fluids influence the corrosion resistance property of the machined surface. In this study, chlorinated paraffin (CP), which is a common additive in the cutting fluid, was selected as the research objective to study its corrosion resistance property. The passivation effect of CP with different concentrations on the machined surface of stainless steel was studied. Electrochemical measurements and surface morphology investigation were used to characterize the passivation effect of CP with different concentrations. The test results showed that the corrosion resistance of stainless steel in the cutting fluid was enhanced with the increase in CP additive. This reason is that the charge transfer resistance increases and the corrosion current density decreases with the increase in CP additive. The X-ray photoelectron spectroscopy (XPS) results show that the proportion of metal oxides on the processed surface of the stainless steel sample was increased from 20.4% to 22.0%, 32.9%, 26.6%, and 31.1% after adding 1 mL, 2 mL, 4 mL and 6 mL CP in the cutting fluid with a total volume of 500 mL, respectively. The oxidation reaction between CP and the stainless steel sample resulted in an increase in metal oxides proportion, which prevented the stainless steel sample from corrosion in cutting fluid.

MATHEMATICAL MODELING OF THE CORROSION BEHAVIOR OF AUSTENITIC STEELS IN CHLORIDE-CONTAINING ENVIRONMENTS DURING THE OPERATION OF PLATE HEAT EXCHANGERS

Purpose. It consists in the development of mathematical models that describe the dependence of the critical pitting temperatures of AISI 304, 08X18N10, AISI 321, 12X18N10T steels in model circulating waters with pH 4...8 and chloride concentration from 350 to 600 mg/l.
 Research methods. The developed mathematical models are based on linear square regression and a neural network of direct signal propagation for a reduced set of features.
 Results. It was established that the critical pitting temperatures of the studied austenitic chrome-nickel steels increase with an increase in the pH of the circulating water, the number of oxides up to 3.95 μm in size, the average distance between titanium nitrides, the Cr content and a decrease in the concentration of chlorides in the circulating water, the average distance between oxides, and the austenite average grain diameter.
 Scientific novelty. Based on the established relationships between the critical pitting temperatures of corrosion-resistant steels AISI 304, 08Х18Н10, AISI 321, 12Х18Н10Т, their chemical composition within the standard and structural heterogeneity, the mechanisms of their influence on the pitting resistance of these structural materials in circulating chloride-containing waters have been developed. It was established that metastable pitting is formed in a solid solution of austenite of steels around oxides with a size of 1,98...3,95 microns and repassivates before reaching critical dimensions of about 5 microns, which contributes to the growth of their pitting resistance in reversible chloride-containing environments.
 Practical value. The developed mathematical models are proposed to be used for the selection of optimal melts of austenitic chrome-nickel steels for the production of heat exchangers and prediction of their pitting resistance during their operation in circulating waters. The processes contributing to the perforation of heat transfer elements of heat exchangers during their operation have been identified.

The corrosion response of the heterogeneous nitriding structure originated from the laser additive manufactured steel

Corrosion of the laser additive manufactured (LAM) steel attracts increasing attentions. In this work, plasma nitriding was carried out to improve the strength and corrosion resistance of LAM 18Ni300 maraging steel at the same time. Nitriding of the as-fabricated sample obtains a heterogeneous nitriding structure with typical LAM dendrite boundaries. Nanosized N-rich grains and associated N-depleted grains were found along the LAM dendrite boundaries, which are beneficial for pitting resistance. Moreover, the corrosion reaction of the nitrided surface is confirmed as γ′/γ + O → MeO(N) + Me+, (Me = Fe, Co, Ni, Mo).

Effects of external loads on microstructure and properties of P92 steel

During the metal-solid phase transition, the mechanical properties of metal materials are affected by the nucleation rate and growth rate of grain. In this work, external loads (200 N, 400 N, 600 N, and 800 N) were applied to P92 steel during the heat treatment process in an attempt to improve and optimize the microstructure and mechanical properties of P92 steel. The effects of different external loads on the morphology, corrosion resistance, microhardness, and mechanical properties of P92 steel were investigated by using optical microscopy, microhardness testing, electrochemical testing, tensile strength measurements, and semi-automatic impact tester. The results show that the grain growth rate of P92 steel was moderate under an external load of 600 N; the grain distribution was uniform and orderly whereas the microhardness and corrosion resistance of the sample reached the optimum value (528 Hv). The tensile strength, yield strength, and elongation of the sample were 786 MPa, 525 MPa, and 37.8 %, respectively. However, the impact power of the P92 steel under an external load of 200 N was the minimum, and its average value was 132 J. The results depict that the external load can improve the mechanical properties of P92 steel.

Study on Corrosion Behavior and Mechanism of Ultrahigh-Strength Hot-Stamping Steel Based on Traditional and Compact Strip-Production Processes.

Hot-stamping steel is a type of high-strength steel that is mainly used in key safety components such as the front and rear bumpers, A-pillars, and B-pillars of vehicles. There are two methods of producing hot-stamping steel, i.e., the traditional process and the near net shape of compact strip production (CSP) process. To assess the potential risks of producing hot-stamping steel using CSP, the microstructure and mechanical properties, and especially the corrosion behavior were focused on between the traditional and CSP processes. The original microstructure of hot-stamping steel produced by the traditional process and the CSP process is different. After quenching, the microstructures transform into full martensite, and their mechanical properties meet the 1500 MPa grade. Corrosion tests showed that the faster the quenching speeds, the smaller the corrosion rate of the steel. The corrosion current density changes from 15 to 8.6 μA·cm-2. The corrosion resistance of hot-stamping steel produced by the CSP process is slightly better than that of traditional processes, mainly since the inclusion size and distribution density of CSP-produced steel were both smaller than those of the traditional process. The reduction of inclusions reduces the number of corrosion sites and improves the corrosion resistance of steel.

Field corrosion study of 690 MPa grade Sb-containing high strength bridge steel in tropical oceanic environment

Bridge steel is developing towards high strength, lightweight and high corrosion resistance. Sb element is reported to be able to improve the corrosion resistance of steel in marine environments. However, current research focuses on the corrosion behavior of low-strength or Cu/Ni/Cr-added bridge steel and pays little attention to Sb-containing high strength bridge steel. Thus, this paper examined the corrosion behavior of a new 690 MPa grade Sb-containing high strength bridge steel through field exposure in a tropical marine atmosphere. The corrosion rate of the steel was calculated by the weight loss method, and the corrosion characteristic and product properties were investigated by SEM, LSCM, EDS and XRD. Results showed that the corrosion rate decreased from 68.69 to 54.88 µm/y as the exposure time increased from 6 to 24 months. The decrease was due to the improvement of corrosion products and the weakening of acidification process. Specifically, the corrosion products became compact and electrochemically stable, and the γ-FeOOH was transformed into Fe3O4 and α-FeOOH with the extension of exposure time. This paper reported for the first time the corrosion evolution process of the 690 MPa grade Sb-added high strength bridge steel in a real marine atmosphere, which is of great significance for the material selection and anti-corrosion design of bridges in the future.

Improved corrosion resistance of 42CrMo4 steel by reconstructing surface integrity using ultrasonic surface rolling process

The ultrasonic surface rolling process (USRP) was adopted to improve the corrosion resistance of 42CrMo4 steel by reconstructing the surface integrity in terms of surface roughness, microhardness, residual stress, and microstructures. The corrosion behaviors of 42CrMo4 steel were studied by salt spray corrosion, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The results indicated that the surface integrity of 42CrMo4 steel was restructured after USRP with the surface roughness reduced to 0.052 µm, the surface microhardness improved to 305 HV0.1, the residual compressive stress achieved up to − 274 MPa at 0.6 mm depth, and the average grain diameter minimized to 2.02 µm in the zone of 5–150 µm depth. Owing to the modified surface roughness, hardened layer, and induced residual compressive stress, the corrosion resistance of 42CrMo4 steel was enhanced by USRP with the annual corrosion rate of 2.972 mm/a reduced about 5.2 %, the corrosion current density of 2.748 μA·cm−2 decreased up to 45.2 %, and the charge transfer resistance of 1809 Ω·cm2 increased up to 19.6 %.

Corrosion Behaviors of N80 and 1Cr Tubing Steels in CO2 Containing Downhole Environment—A Case Study of Underground Gas Storage in LiaoHe Oil Field

In order to evaluate the effect of chromium content in carbon steel on the corrosion resistance of carbon steel materials, the corrosion behavior of 1Cr and N80 steels was investigated in this study by immersion weight loss method under three different CO2 partial pressure and temperature conditions in formation water for 72, 168 and 336 h. Detailed material surface morphological characterization was performed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and confocal laser scanning microscopy (CLSM). The results show that the pitting corrosion of N80 carbon steel is serious at medium temperature and low CO2 partial pressure (50 °C, 0.30 MPa), and the corrosion rate is significantly higher than that of 1Cr steel. However, at high-temperature and high CO2 partial pressure (100 °C/0.63 MPa and 114 °C/0.73 MPa), 1Cr steel is more inclined to the mesa corrosion dominated by local corrosion characteristics, and the corrosion rate is seriously higher than that of N80 steel with uniform corrosion. From the experimental results, we can know the corrosion resistance of carbon steel and 1Cr steel is not only affected by the corrosion environment, but also depends on the formation process of the product film, as well as its compactness and integrity characteristics. At low-temperature and low CO2 partial pressure, 1 wt.% chromium content can provide a certain degree of corrosion resistance, while high temperature and high partial pressure can broaden the application window of carbon steel N80 and weaken the corrosion inhibition effect of chromium.

The Influence of Heat Treatments in Corrosion Resistance of Austenitic Steels

Abstract This paper presents the results of laboratory research on the influence of heat treatment on the corrosion resistance of austenitic steels (Cr-Ni, Cr, Mn, Cr-Mn-Ni), research that may extend under certain conditions and ferrites steels and semi-ferrites chrome steels.This type of intercrystalline corrosion was observed in other alloy systems due to media containing chloride ions.The experimental results consist in comparing structural changes and corrosion rate for different types of austenitic steels that were made experimental research.

Corrosion resistance of austenitic stainless steel using cathodic plasma electrolytic oxidation

Substantial improvement of corrosion resistance of austenitic stainless steel (SS) has been demonstrated with a protective oxide layer formed by the cathodic plasma electrolytic oxidation (CPEO) process. Two distinct layers, a porous-structured outer layer comprising Fe oxides and a compact inner layer comprising Cr oxides, were created on the SS surface after the CPEO process. The thicknesses of the outer and inner layers were approximately 7 μm and 12 μm, respectively, and the oxide layers were fabricated in an exceptionally short time of <30 s. A potentiodynamic polarization analysis exhibited a 65 % decrease in the corrosion current after the formation of the protective oxide layer, verifying the effectiveness of the CPEO treatment on the corrosion resistance of SS. An electrochemical impedance spectroscopy study revealed that the outer layer captured corrosive species due to its porous structure, while the inner layer had high resistance to reactions with corrosive species due to the compact structure of Cr oxides. Additionally, a Rockwell C indentation test demonstrated the robust mechanical property of the protective oxide layer with a strong bonding strength to the substrate.

Study of various base materials with zinc and nano particle coatings

Study of the various base material mechanical properties to enhance the strength, hardness, durability, surface morphology, micro structure, etc. along with cost efficient is done. The coating is carried out on high chromium steel and mild steel materials by using zinc thermal spray process. Properties are investigated by zinc coating with carbon based nano particles (Graphene) and its effect on the mechanical properties. Lots of researchers are working on different materials and various coatings in manufacturing segment to improve production, cost and quality with environmental concerns of world. The materials may be failed due to lack of mechanical properties like wear resistance, strength, corrosion resistance, hardness, toughness etc. To overcome this type of problems, need to apply coatings to substrate material in proper proportion for achieving desirable mechanical properties. The issues that arise during high temperature coating preparation methods, such as laser cladding and thermal spraying, are first briefly discussed in this overview. Metals are under cooled frozen liquids in the form of bulk metallic glasses. Nano particle structural reinforcement are 100 times stronger than steel and the polymer materials electrical conductivity can be enhanced by using conductive fillers like carbon nano particles in incorporation. It also reveals that corrosion resistance of mild steel can be improved after coated with nano particles (Graphene).

Effect of addition of alumina and rare-earth oxide particles on the corrosion resistance and mechanism of low carbon low alloy steel

The corrosion mechanism of the low carbon low alloy steel with Al2O3 particles and rare Earth (RE) oxide particles was compared in a simulated marine environment. It is shown that when the Al2O3-containing particles are introduced, the number density of nonmetallic particles of the steel increases twice, and the average particle size decreases from approximately 2.4 μm to 1.4 μm. With the introduction of Al2O3-containing particles, the amount of pitting corrosion increases. Furthermore, pitting corrosion occurs more uniformly owing to the fineness of the Al2O3 particles, thereby leading to smaller, shallower pits after the Al2O3 particles are shed. Hence, the corrosion performance of the steel with Al2O3 particles is significantly improved than that of the steel without Al2O3 particles. By adding RE oxide particles into steel, the nonmetallic particles in steel are refined but not as effectively as that achieved by adding the Al2O3-containing particles. Different from Al2O3 particles, Cu is obviously enriched in the location of RE oxide particles at the initial corrosion stage, which makes the steel exhibit the best corrosion resistance. Cu enrichment is attributed to the mobile Cu present in the rust layer and to the micro acid region formed around the RE oxide particles.

Comparative Studies on Steel Corrosion Resistance of Different Inhibitors in Chloride Environment: The Effects of Multi-Functional Protective Film

A corrosion inhibitor was widely used to improve corrosion resistance of steel bar in reinforcement concrete structure. A kind of multi-component corrosion inhibitor, which is composed of organic and inorganic substances, was developed in this research. This corrosion inhibitor was comparatively studied with various other inhibitors by using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) methods. The results show that the OCP values and charge transfer resistance (calculated by EIS curves) of the multi-component corrosion inhibitor remain, respectively, as high as −0.45 V and 932.19 kΩ·cm−2 after 60 days immersion, which are significantly better than other groups. Wide passivation interval and various peaks in cyclic voltammograms (CV) were applied to analyze the mechanism of adsorption (organic substance) and oxidation–reduction reactions (inorganic substance). The functional groups -OH in triethanolamine (TEA) and tri-isopropanolamine (TIPA) bond to the steel bar surface quickly, behaving as an adsorbent of organic substance in early age. An additional protective precipitate related to the reactions of Fe3+ was formed by inorganic substances (Fe2(MoO4)3 and FePO4), which is consistent with the EIS results and equivalent electrochemical circuits. As an eco-friendly substitute, multi-component corrosion inhibitors possess similar or even better protecting effects on steel bars in comparison to calcium nitrite. In addition, the concept of a “multi-functional protective film” was proposed, providing a new insight to achieve modified anti-corrosion capacity of inhibitors.

Vibrational Spectroscopy and electrochemical study of MCuP2O7 (M = Ba, Ca and Zn), improvement of corrosion resistance of mild steel in 1.0 M HCl medium

The three diphosphates materials MCuP2O7(M = Ba, Ca and Zn) were synthesized by solid-state reaction and characterized. Using X-ray powder diffraction, infrared and Raman spectroscopy. The external and internal normal modes of these materials were studied by the factor group analysis. The analysis of the infrared and Raman spectra shows the non-linearity of the POP bridge. And also, that the structures of these salts are centrosymmetric. These materials have been studied in order to investigate its electrochemical behavior for corrosion resistance of mild steel in a corrosive medium (HCl 1.0 M). The inhibition performance of the three materials was evaluated by the open circuit potential (OCP), potentiodynamic polarization technique (PDP) and electrochemical impedance spectroscopy (EIS). The morphology of mild steel was examined by scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results show that the three materials have good efficiency for the mild steel corrosion inhibition with a percentage reaches 89% for Ba based material.

Comparison of Metastable Pitting Behavior of Austenitic and Duplex Stainless Steels under U‐Bending Deformation

The metastable pitting behavior of austenitic stainless steel (304 SS) and duplex stainless steel (2205 DSS) under U‐bending deformation is comparatively investigated. This study highlights the effects of differences in inclusions and matrix between 304 SS and 2205 DSS with regard to the metastable pitting behavior under tensile and compressive deformation. The results show that the pit initiation frequency of 304 SS increases in the order: tensile &lt; as‐received &lt; compressive; in contrast, the initiation frequency of 2205 DSS increases in the order: as‐received &lt; tensile &lt; compressive. In addition, tensile and compressive deformation change the preferential initiation sites of metastable pitting in 2205 DSS. It is proposed that the types of transient signals can be comprehensively and objectively distinguished by the two parameters (t g/t rep) and [(I p/Q g):(I p/Q rep)]. The correlation relationship between transient signals and pitting morphologies is clarified by cluster analysis. Both tensile and compressive deformations promote the growth of a few metastable pits, thus increasing the transition probability from metastability to stability. Overall, both tensile and compressive deformations are detrimental to the pitting corrosion resistance of the experimental steels.

Effect of Nb on microstructure and corrosion resistance of X80 pipeline steel

In this study, a series of χNb-X80 pipeline steels were obtained by adding different contents of Nb to X80 pipeline steel and after different cooling rates. The effects of Nb on the microstructure and corrosion resistance of X80 pipeline steel were studied by metallographic microscope, scanning electron microscope, differential scanning calorimeter, electrochemical corrosion, and salt spray corrosion. The results show that the high cooling rate will hinder the phase transformation, reduce the diffusion ability of Nb element at the grain boundary, inhibit the growth rate of ferrite grains, and refine the grains of the sample steel structure. The grain refinement effect is the best when the cooling rate is 40 °C/min. In addition, the reason why Nb improves the corrosion resistance of X80 pipeline steel is discussed from two aspects: the change of corrosion products and the effect of grain refinement. The analysis shows that Nb promotes the formation of a dense corrosion protective film, and this positive effect of the protective film overcomes the negative corrosion effect caused by the grain refinement caused by the precipitated Nb (CN), thereby enhancing the corrosion resistance of the substrate. The corrosion resistance is the best when the Nb content is 0.16 wt %.