Corrosion Resistance Of Stainless Steel Research Articles

Effect of Alloying Elements and Low Temperature Plasma Nitriding on Corrosion Resistance of Stainless Steel.

Although nitriding treatment usually improves the hardness and wear resistance of stainless steel, it also reduces its corrosion resistance. The effects of different nitriding temperatures and time and main alloying elements in stainless steel on the properties of the martensitic precipitation hardening of stainless steel were studied by first-principles calculations and experiments in this study. The results showed that the corrosion resistance of the martensitic stainless steel 0Cr17Ni4Cu4Nb was much lower than that of 1Cr15Ni2Mo2Cu before and after nitriding. According to the density functional theory calculation results, the molybdenum-containing stainless steel had higher stability and corrosion resistance and a lower Fermi level, electron conduction concentration and electrochemical activity than the niobium-containing stainless steel before and after nitriding. In addition, at the same temperature, the surface hardness of the 1Cr15Ni2Mo2Cu steel increased linearly with the prolongation of nitriding time, but its corrosion resistance decreased. Under the same nitriding time (24 h), the nitriding temperature increased from 300 to 450 °C, and the surface hardness and nitriding layer depth of the nitriding steel increased gradually, while the corrosion resistance decreased gradually. These results were attributed to the Cr-poor phenomenon caused by the formation of CrN. The 1Cr15Ni2Mo2Cu martensitic stainless steel obtained a high surface hardness after nitriding at 300 °C for 24 h, and the corrosion resistance did not decrease.

Construction of corrosion resistant stainless steel mesh and the design for protecting optical window free from biofouling

Bio-fouling impedes widespread application of sensors for marine environmental monitoring. It is an issue to develop a simple and mitigating membrane fouling attachment device. In this work, an antifouling and corrosion resistant 316ss mesh combining with 3D printing was used to develop a novel device model for protecting the optical window free from biofouling under sea water. The Ag coating 800# 316ss mesh exhibited the most antifouling effect on protecting the glass not only among the different pore size, but also comparing with the naked mesh at the same pore size in natural water. However, the corrosion occurred on the Ag coating 316ss mesh in the seawater. After Al2O3 pre-deposited on 316ss mesh prior coating Ag film, the multilayered Al2O3/Ag 316ss mesh were prepared successfully. To simulate experiment of protection optical window in the sea, a proper device was designed through 3D printing combined with the functional 316ss mesh, which exhibited an outstanding antifouling capacity as long as 30 days and without corrosion. This strategy demonstrated a realistic paradigm of combining 3D printing technology with the antifouling materials to design a simple and mitigating membrane fouling attachment device for commercially available sensors in the further application.

Corrosion Resistance of Laser Powder Bed Fused AISI 316L Stainless Steel and Effect of Direct Annealing.

Alloy parts produced by an additive manufacturing method with rapid heat transfer from fast melting and solidification have different microstructures, characteristics, and performances compared with materials made by the conventional process. In this study, the corrosion and oxidation resistance of SS316L, which was prepared by the powder bed fusion process, was compared with those of cold-rolled SS316L. Additionally, the surface oxide film on stainless steel was thoroughly assessed since the film has the greatest influence on the corrosion and oxidation resistance. The effect of heat treatment on corrosion and oxidation resistance of SS316L fabricated by additive manufacturing was investigated. The SS316L has a microstructure formed by sub-grain cells, in which locally concentrated alloying elements form a stable passive film. As a result, it has a higher level of corrosion resistance and oxidation resistance than conventional cold-rolled materials. However, it was confirmed that the sub-grain cell was removed by heat treatment, which resulted in the degradation of corrosion and oxidation resistance.

ELECTRODEPOSITION OF CHROMOXIDE COATINGS FROM ELECTROLYTES MODIFIED WITH SiO2·nH2O

To increase the corrosion resistance of stainless steel from local types of corrosion, chromium oxide coatings obtained from electrolytes modified with SiO2·nH2O were applied to its surface. It has been established that the coatings obtained from the electrolyte with the addition of SiO2·nH2O are continuous, without cracks, and finely crystalline compared to the coating obtained from the base electrolyte. Elemental analysis did not show the presence of silicon in the composition of the coating obtained from the modified SiO2·nH2O electrolyte, however, it showed the presence of a larger amount of chromium compared to the coating obtained from the base electrolyte. On the polarization curves, there is a complication of the release of hydrogen at the cathode and oxygen at the anode, which indicates a decrease in the electrical conductivity of the obtained coatings. The results obtained make it possible to recommend the use of SiO2·nH2O additives to the electrolyte to obtain chromium oxide coatings on steel with enhanced corrosion protection properties.

Effect of Grain Size on the Pitting Corrosion Resistance of Lean Duplex Stainless Steel

The effects of grain refinement on the resistance to pitting corrosion and passive film properties of lean duplex stainless steel (Fe–18.28Cr–5.68Mn–2.38Mo–0.39W–0.30N–0.035C, wt%) are studied. For this purpose, the grain size of this alloy is adjusted to 3, 7, and 17 μm through an annealing process after cold rolling. The pitting corrosion resistance is evaluated through potentiodynamic polarization tests in aqueous solutions containing Cl−. The grain size reduction enhances the resistance to pitting corrosion of the alloy. Mott–Schottky analysis and X‐Ray photoelectron spectroscopy analysis on the passive films show that, as the grain size decreases, the density of point defects of the film decreases, the film thickness increases, and the cation fraction of Cr of the film increases. The improved resistance to pitting corrosion by grain refinement is attributed to the formation of the thick and dense passive film with a high Cr content.

Effect of Cold Rolling and Subsequent Annealing on the Corrosion Resistance of Ag-Containing CD4MCu Duplex Stainless Steels

Effect of Cold Rolling and Subsequent Annealing on the Corrosion Resistance of Ag-Containing CD4MCu Duplex Stainless Steels

Improving corrosion resistance of selective laser melted 316L stainless steel through ultrasonic severe surface rolling

Selective laser melting (SLM) is one of the common methods of additive manufacturing and herein, ultrasonic severe surface rolling (USSR) is applied to enhance the corrosion resistance of SLM 316L stainless steel (SS) in the 3.5% NaCl solution. USSR produces a thick (∼1 mm) gradient surface layer with a nanostructured, chemically homogeneous, and high-quality surface but a small amount of martensite. The USSR processed 316L SS exhibits significant enhancement in the corrosion resistance compared to the SLM one, as manifested by the greatly improved pitting potential, decreased passive current density, and reduced corrosion current density. The superior corrosion properties stem from the unique gradient structure with a high density of grain boundaries and chemically homogeneous and high-quality surface facilitating the formation of a thicker and more protective passive film that contains larger contents of oxides and hydroxides of Fe and Cr in spite of almost the same total Cr concentration. In addition to the high strength and ductility, the unique gradient structure endows the SLM 316L SS with superior corrosion resistance and long service lifetime in the marine environment, boding well for application to marine equipment and engineering.

Improvement in corrosion resistance of 316L stainless steel in simulated body fluid mixed with antiplatelet drugs by coating with Ti-doped DLC films for application in biomaterials

The structures of pure (DLC), 5.33 at% Ti-doped (DLC:Ti_1), and 15.24 at% Ti-doped (DLC:Ti_2) DLC films coated on 316L SS were investigated using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. Their corrosion behavior was studied using electrochemical techniques. DLC:Ti_1 exhibited outstanding corrosion resistance with the lowest icorr and highest Rp. Its corrosion resistance improved further when antiplatelet drugs [ticlopidine (T1) and aspirin (A1)] were present in the simulated body fluid (SBF), as indicated by the increase in the inhibition efficiency of DLC:Ti_1-SBF from 84.21 to 93.26 and to 97.04% for both DLC:Ti_1-A1 and DLC:Ti_1-T1, respectively.

Effect of anodic polarization treatment on microbiologically influenced corrosion resistance of Cu-bearing stainless steel against marine Pseudomonas aeruginosa

Anodic polarization treatment was used to investigate microbiologically influenced corrosion (MIC) behavior of 316 L-Cu stainless steel (SS) against marine Pseudomonas aeruginosa using electrochemical tests and morphology observation techniques. The results indicated that anodic polarization treatment endowed 316 L-Cu SS with a decreased corrosion current and increased pitting potential in comparison with conventional 316 L SS and 316 L-Cu SS incubated in a biotic medium. The surface morphology observations combined with XPS analysis found that 316 L-Cu SS effectively inhibited bacterial reproduction and promoted the formation of a dense protective extracellular polymeric substance (EPS)-Fe membrane, leading to less susceptibility to pitting corrosion than 316 L SS.

Improving the wear and corrosion resistance of martensitic stainless steel by paste boriding treatment

Surface hardening techniques of steel are of great practical interest for applications in the petroleum industry. The boriding technique is one of the most economical choices. In this work, a paste boriding process is performed to increase the wear and corrosion resistance of AISI 410 martensitic stainless steel. The surface wear and corrosion resistance of the steel were significantly improved via the paste boriding treatment. The microstructure of the borided layer consists of FeB and Fe2B, which are located in the external and internal layers of the borided layer, respectively. As the boriding temperature rises, the thickness of the borided layer increases, which at the same time leads to an increase in the number of voids.

Improved Mechanical and Corrosion Properties of Powder Metallurgy Austenitic, Ferritic, and Martensitic Stainless Steels by Liquid Phase Sintering.

Powder metallurgy (PM) has been widely used to produce various steels in industry, mainly due to its capabilities for manufacturing nearly net-shaped products and mass production. To improve the performances of PM stainless steels, the roles of 0.6 wt% B additive in the microstructures, mechanical properties, and corrosion resistances of PM 304L austenitic, 410L ferritic, and 410 martensitic stainless steels were investigated. The results showed that adding 0.6 wt% B significantly improved the sintered densities of the three kinds of stainless steels due to the liquid phase sintering (LPS) phenomenon. The borides in 304L + 0.6B, 410L + 0.6B, and 410 + 0.6B were rich in B and Cr atoms but deficient in Fe, Ni, or C atoms, as analyzed by electron probe micro-analysis. Furthermore, the B additive contributed to the improved apparent hardness and corrosion resistance of PM stainless steels. In the 410L stainless steel, the 0.6 wt% B addition increased the corrosion voltage from −0.43 VSCE to −0.24 VSCE and reduced the corrosion current density from 2.27 × 10−6 A/cm2 to 1.93 × 10−7 A/cm2. The effects of several factors, namely: porosity; the generation of boride; the matrix/boride interfacial areas; Cr depletion; and the microstructure on the corrosion performances are discussed. The findings clearly indicate that porosity plays a predominant role in the corrosion resistances of PM austenitic, ferritic, and martensitic stainless steels.

Corrosion resistance of laser melting deposited Cu-bearing 316L stainless steel coating in 0.5 M H2SO4 solution

To improve the corrosion resistance of stainless steel, the microstructure and corrosion resistance of a Cu-bearing 316 L stainless steel coatings prepared by laser melting deposition (LMD) in 0.5 M H2SO4 solution were mainly investigated. The results showed that Cu can enrich in the dendrite to form FCC ε-Cu in the 316 L stainless steel, while possessing little affect on the microstructure morphology. The Cu addition facilitates the corrosion products forming in the interdendritic of coating, which protects the coating surface from being etched, improving its corrosion resistance in 0.5 M H2SO4 solution. With the Cu content increasing from 0 wt% to 7.52 wt%, the open circuit voltage of coating increases from −302.8 mV to −116.2 mV, the corrosion current density decreases from 1.64 × 10−3 μA cm−2 to 1.54 × 10−6 μA cm−2, and the polarization resistance increases from 36.9 Ω∙cm2 to 14240.3 Ω cm2.

Investigation of the corrosion of stainless steel, copper and aluminium in sunflower biodiesel solution: Experimental and theoretical approaches

The increase in energy has created a clear imbalance between the availability and usage of these resources, prompting the industry to resort to biofuels. The main objective of this study is to investigate the corrosion resistance of materials used as biofuel production reactors (stainless steel (SS), aluminium (Al), and copper (Cu)) during sunflower biodiesel production. The corrosion resistance of stainless steel, aluminium, and copper was investigated using electrochemical monitoring techniques such as open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). Throughout this work, spectroscopic methods, including Fourier transform infrared (FTIR), GS/MS, UV absorption, SEM/EDS, and X-ray diffraction (XRD), have been used to thoroughly examine the surfaces of the metals and the composition of the biodiesel after testing. All metals examined showed excellent corrosion resistance, attributed to the formation of such a passivation film on their surfaces, as shown by the EIS data. SEM/EDS analysis confirmed that the methyl esters had a slight impact on metal deterioration, with a modest corrosion rate and the formation of localized micro-pitting on the metal surface. The FAAS analysis also revealed the existence of a low concentration of metal ions released into the solution. Therefore, the correlation approach (DFT and molecular dynamics simulations (MDS)) was applied to support the experimental results that favoured aluminium as the base metal for biodiesel synthesis due to its low corrosion rate during the process.

Corrosion behavior of CoCrNiMoBC coatings obtained by laser cladding: Synergistic effects of composition and microstructure

In order to improve corrosion resistance of stainless steels, a CoCrNiMoBC coating was prepared by laser cladding. The microstructure, composition, and crystallographic orientation relationships of the coating were discussed. Electrochemical methods were used to evaluate its corrosion behavior. Results showed that the coating had remarkable resistance to chloride ion corrosion under strongly acidic conditions. The critical pitting temperature of the coating was higher than 80 °C in both neutral and acidic chloride ion environments. Immersion tests confirmed that pits did not expand significantly after 10 days immersion in 5 M HCl solution. The excellent corrosion resistance stemmed from a stable passivation film formed due to the synergistic effects of composition and microstructure.

Influence of Anodization Condition on Hydrophobicity, Morphology, and Corrosion Resistance of 17-4PH Stainless Steel

Influence of Anodization Condition on Hydrophobicity, Morphology, and Corrosion Resistance of 17-4PH Stainless Steel

Anisotropy of microstructure and corrosion resistance of 316L stainless steel fabricated by wire and arc additive manufacturing

This study investigated the dependent relationships between the microstructure and corrosion resistance of the 316L part using wire and arc additive manufacturing (WAAM), through electrochemical methods and multiscale characterization techniques. The results showed that the corrosion resistance strongly depended on anisotropy in the microstructure. On the top surface, fewer track-track fusion lines with weaker element segregation led to the best pitting corrosion resistance. But on the side surface perpendicular to the scanning direction, the narrower ferrite primary dendrite arm spacing, lower ferrite content and more uniform element distribution provided the best general corrosion resistance.

Corrosion mechanism of eutectic high-entropy alloy induced by micro-galvanic corrosion in sulfuric acid solution

The corrosion behavior of AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA) in aerated 0.5 M H2SO4 solution was investigated. The initial and long-term corrosion of EHEA were respectively controlled by the micro-galvanic corrosion cells established between Cr-rich FCC (cathode) and Al-rich/Cr-depleted BCC (anode) phases and between the lamellar (anode) and irregular (cathode) regions. Correspondingly, the main corrosion type of EHEA transformed from the preferential dissolution of BCC phase to the predominant localized corrosion of the whole lamellar region. EHEA exhibited electrochemical passivation property comparable to 304 L stainless steel and superior corrosion resistance relative to most Al-containing dual-phase HEAs.

Study on Corrosion Behavior of Simulated Welding Microstructure of Austenitic Stainless Steel

In this paper, the simulated welding structure of austenitic stainless steel is prepared by external heating, and the corrosion resistance of austenitic stainless steel in different areas of heat affected zone (HAZ) is evaluated by means of metallographic structure analysis, electrochemical impedance spectroscopy (EIS) test and equivalent circuit numerical fitting analysis. The result shows that the simulated welding structure of austenitic stainless steel had a growth trend with the increase of heating temperature, but the growth trend is not very obvious. The short thermal process has insufficient driving force for the growth of single-phase austenitic structure. The resulting of product resistance and charge transfer resistance of simulated welding microstructure of austenitic stainless steel is not completely consistent. The simulated welding microstructure of stainless steel shows the tendency of corrosion resistance degradation with the heating temperature increasing, and it has slightly lower when the maximum heating temperature locating at 1000-1100 °C.

Comparison of the Properties of Additively Manufactured 316L Stainless Steel for Orthopedic Applications: A Review

Owing to the low cost, ease of fabricability, good mechanical properties, corrosion resistance and biocompatibility of the 316L stainless steel (SS), this material is considered a suitable choice for orthopedic applications. Based on its properties and large utilization in orthopedics, this review focuses on the importance of additively manufactured (AM) 316L stainless steel. Owing to the large flexibility of the additive manufacturing process, the microstructure of the 316L SS can be easily tuned to modify the mechanical, corrosion and biological properties. To elucidate the benefits of additively manufactured 316L stainless steel, the properties of the selective laser melted (SLM) 316L stainless steel and wrought 316L stainless steel are compared. Particularly, the unique features of the SLM 316L stainless steel have been discussed in detail. The existing challenges associated with the additive manufacturing processes and implications of their widespread application are also highlighted. A brief overview of the biological properties and reactions sequence of the host immune system, i.e. tissue response, the activation of acute and chronic inflammatory processes and immunological reactions, is also provided to understand the reasons for implant failure or rejection by the body.

Investigation of the ultrasonic welded stainless steel corrosion resistance

This article will present the ultrasonic welding technology of the stainless steel sheets, the joining with agreeing of the material science theory and metal-working rules-based executed experiments. Fusion welding is well understood and investigated in the case of steel. The ultrasonic welding in the case of metals causes different changes in the metals structure. The ultrasonic welding cause complex effect during the welding process. These effects are plastic deformation, heat, and ultrasound vibration. The goal of this research is to show the case of the experimented welded stainless steel (X5CrNi18-10) to determine the corrosion behaviour by non-destructive (visual test and microscopy) inspections. The stainless steel is sensible for all processes even that the cold working, heating and ultrasound effect. These effects can cause a decrease in the corrosion resistance of stainless steel.