scholarly journals Effect of nano-grain carbide formation on electrochemical behavior of 316L stainless steel

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chatdanai Boonruang ◽  
Wutipong Sanumang

AbstractThe effect of low oxygen-partial pressured carburizing on relaxation process for 316L stainless steel is reported. Phase, morphology, and amount of compound formation during initial stage of carburizing are investigated using X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The results show formation and development of surface multilayer with nano-grain-carbide (Cr7C3, Fe7C3, and/or Cr3C2) generation in the layer located below outermost protective layer. The relaxation process has been investigated using electrochemical impedance spectroscopy (EIS). Formation of nano-grain carbide(s) during carburizing causes deterioration effect on the electrochemical behavior of steel. However, the steel with large amount of carbide generation (carburized for 30 min) tends to have higher corrosion resistance (indicated by higher values of Rcl and Rct) than the smaller ones (10 and 20 min) due to the effect of phase, grain size, morphology, and amount of compound formation.

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 636 ◽  
Author(s):  
Xu ◽  
Wang ◽  
Chen ◽  
Qiao ◽  
Zhang ◽  
...  

The effect of rare earth oxides on the microstructure and corrosion behavior of laser-cladding coating on 316L stainless steel was investigated using hardness measurements, a polarization curve, electrochemical impedance spectroscopy (EIS), a salt spray test, X-ray diffraction, optical microscopy, and scanning electron microscopy (SEM). The results showed that the modification of rare earth oxides on the laser-cladding layer caused minor changes to its composition but refined the grains, leading to an increase in hardness. Electrochemical and salt spray studies indicated that the corrosion resistance of the 316L stainless steel could be improved by laser cladding, especially when rare earth oxides (i.e., CeO2 and La2O3) were added as a modifier.


Author(s):  
Wei Han ◽  
Fengzhou Fang

Abstract The study is to investigate the electropolishing characteristics of 316L stainless steel in a sulfuric acid-free electrolyte of phosphoric acid and glycerol and to explore the possibility of using this eco-friendly electrolyte instead of the widely used sulfuric acid-based electrolyte. The influences of process parameters on polishing effects and the corrosion resistance of electropolished samples are investigated. The experimental results show that the electropolishing temperature and acid concentration are directly related to the mass transport mechanism in the limiting current plateau region. The grain boundaries of workpiece were electrochemically dissolved faster than the grain themselves at the beginning of the electropolishing process because they are more reactive than grains. Moreover, the conventional sulfuric—phosphoric acid electrolyte was also used to electropolish the 316L stainless steel, and the electropolished surfaces were compared with the sulfuric acid-free electrolyte proposed in this study. When the sulfuric acid-free electrolyte was used to electropolish the 316L stainless steel, the X-ray photoelectron spectroscopy (XPS) analysis shows that atomic Cr/Fe ratio of 316L stainless steel was increased from 0.802 to 1.909 after electropolishing process in the sulfuric acid-free electrolyte of phosphoric acid and glycerol. The corrosion resistance of the electropolished 316L stainless steel is studied using electrochemical analysis, and the results are verified experimentally.


2017 ◽  
Vol 62 (4) ◽  
pp. 2211-2216 ◽  
Author(s):  
M. Dudek

AbstractThe paper presents the analysis of formation of interfacial layer during deposition of diamond like carbon film (DLC) on the 316L stainless steel by capacitive plasma discharge in the CH4atmosphere. The structure of the interfacial layer of DLC film was strongly affected by the temperature increase during the initial stages of the process. Initially, thin interfacial layer of 5 nm has been formed. As the temperature had reached 210°C, the second phase of the process was marked by the onset of carbon atoms diffusion into the steel and by the interface thickness increase. Finally, the growth of chromium carbide interface, the upward diffusion of chromium and nickel atoms to film, the etching and the decrease of the DLC film thickness were observed at 233°C. These investigations were carried out ex-situ by spectroscopic ellipsometry, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jun He ◽  
Lin Chen ◽  
Yanjing Su

Purpose The purpose of this study is to elucidate the effect of Mn addition on the corrosion behavior of stainless steel. Design/methodology/approach Chronoamperometry, quasi-steady-state polarization and electrochemical impedance spectroscopy were used to investigate the corrosion behavior of Mn added A13Cr-HS sample and original S13Cr samples. In addition, the corrosion product film was characterized by a field emission scanning electron microscope equipped with energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. Findings The A13Cr-HS sample with 8 wt.% Mn addition maintained good general corrosion resistance in both acidic and alkaline solutions compared to the original S13Cr sample. Additionally, the A13Cr-HS sample had good pitting resistance in an alkaline solution containing Cl−, but a weaker resistance in an acidic solution. Originality/value The influence of Mn addition on the formation mechanism of the passive film was systematically analyzed.


CORROSION ◽  
10.5006/3230 ◽  
2020 ◽  
Vol 76 (9) ◽  
pp. 884-890
Author(s):  
Renata B. Soares ◽  
Wagner R.C. Campos ◽  
Pedro L. Gastelois ◽  
Waldemar A.A. Macedo ◽  
Luís F.P. Dick ◽  
...  

The electrochemical behavior and the electronic properties of passive films formed on a super martensitic stainless steel (SMSS) used in oil and gas industries were investigated in aqueous 0.6 M and 2.1 M NaCl solutions with additions of sodium acetate and acetic acid (pH 4.5). Open-circuit potential transients, electrochemical impedance spectroscopy, cyclic voltammetry, and x-ray photoelectron spectroscopy were measured to characterize the passive film formed on SMSS. The electrochemical behavior of the steel in an aqueous solution of 0.6 M NaCl presented the highest pitting potential and the highest polarization resistance in relation to the NaCl/NaAc solution. The passive film of SMSS in an aqueous solution of NaCl presented a thickness of 18.40 nm, three times the thickness of the oxide film in NaCl/NaAc, and consisted of FeO, Cr2O3, MoO2, and spinels such as FeCr2O4 species that are a p-type semiconductor, but may also contain a small fraction of the Fe2O3 and MoO3 oxides. Additionally, it was shown that the passive layer after immersion in a saline solution also contains hydroxides such as FeOOH and Cr(OH)3.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6136
Author(s):  
Tung-Yuan Yung ◽  
Hui-Ping Tseng ◽  
Wen-Feng Lu ◽  
Kun-Chao Tsai ◽  
Tien Shen ◽  
...  

Chromia-forming ferritic stainless steel (FSS) is a highly promising interconnect material for application in solid oxide fuel cells. In this study, initial oxidation of chromium oxides was performed at 500–800 °C to understand the evolution of materials at an early stage. The structural variations in oxide scales were analyzed through scanning electron microscopy, energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser confocal microscopy (LSCM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Surface electrochemical properties were investigated through electrochemical impedance spectroscopy to understand how the heat treatment temperature affected surface impedance. Treatment temperatures higher than 700 °C facilitate the diffusion of Cr and Mn, thus allowing ferritic spinels to form on the surface and leading to high electrical conductivity.


Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 506 ◽  
Author(s):  
Sadaqat Ali ◽  
Ahmad Majdi Abdul Rani ◽  
Riaz Ahmad Mufti ◽  
Farooq I. Azam ◽  
Sri Hastuty ◽  
...  

In the past, 316L stainless steel (SS) has been the material of choice for implant manufacturing. However, the leaching of nickel ions from the SS matrix limits its usefulness as an implant material. In this study, an efficient approach for controlling the leaching of ions and improving its properties is presented. The composition of SS was modified with the addition of boron and niobium, which was followed by sintering in nitrogen atmosphere for 8 h. The X-ray diffraction (XRD) results showed the formation of strong nitrides, indicating the diffusion of nitrogen into the SS matrix. The X-ray photoelectron spectroscopy (XPS) analysis revealed that a nitride layer was deposited on the sample surface, thereby helping to control the leaching of metal ions. The corrosion resistance of the alloy systems in artificial saliva solution indicated minimal weight loss, indicating improved corrosion resistance. The cytotoxicity assessment of the alloy system showed that the developed modified stainless steel alloys are compatible with living cells and can be used as implant materials.


2019 ◽  
Vol 9 (2) ◽  
pp. 99-111
Author(s):  
Wejdene Mastouri ◽  
Luc Pichon ◽  
Serguei Martemianov ◽  
Thierry Paillat ◽  
Anthony Thomas

Stainless steels are broadly used thanks to their specific physical properties such as their high corrosion resistance in poorly aggressive solutions. However, only few studies have been reported in the literature concerning their electrochemical behavior in low concentration electrolytes medium. Accordingly, the present work aims to study the immersion time influence on the solid-liquid interface properties of the austenitic stainless steel AISI 304L, immersed in a low-concentrated (0.01 M) sodium chloride (NaCl) solution. The electroche­mical behavior of the interface was evaluated by electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) monitoring. The morphological features and the modification of the surface composition were evaluated by Optic Microscopy, Scanning Electron Microscopy, Energy Dispersive X-ray Spectrometry, Atomic Force Microscopy, White Light Interferometry and X-ray Photoelectron Spectroscopy. It was determined by OCP measurement that the characteristic time of the interface stabilization is very long (several months). After an immersion of 2 months in NaCl solution, a second time constant on impedance phase diagram appears. Surface characterizations reveal a significant modifi­cation of the morphology and chemistry of the AISI 304L surface that can be linked to OCP/EIS observations. It can be noticed that the repeatability deviation of the EIS method was about 1 % while its reproducibility deviation was estimated to 35 %.


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