scholarly journals Corrosion Properties of 34CrMo4 Steel Modified by Shot Peening

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Qiang Zheng ◽  
Kejian Li ◽  
Xueguo Yin ◽  
Bingbing Li ◽  
Chunhong Li ◽  
...  

A nanocrystalline layer was prepared on the surface of 34CrMo4 steel by time controlling shot peening (SP, i.e., 1, 5, 10, and 20 minutes). Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, and transmission electron microscope (TEM) were applied to analyze the surface, cross-sections, and grain size of the specimens before and after SP. The electrochemical corrosion behavior was used to simulate a liquid under the oil and gas wells environment. It was characterized by the potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). The analysis results show that the surfaces of the SP samples were very rough and had numerous cracks. A passive film on SP surface was formed by nanocrystalline grains. However, the passive film formed in the initial stage was not dense or uniform, and cracks occurred in the passive film during peening, resulting in a decrease in corrosion resistance.

2021 ◽  
Vol 904 ◽  
pp. 519-524
Author(s):  
Gui Yun Zhang ◽  
Yong Wang ◽  
Tian Wei Zhang ◽  
Chen Yu Zhao

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3665
Author(s):  
Zahid Ahmed Baduruthamal ◽  
Abdul Samad Mohammed ◽  
A. Madhan Kumar ◽  
Mohamed A. Hussein ◽  
Naser Al-Aqeeli

A new approach of using a polymer hybrid nanocomposite coating to modify the surface of titanium and its alloys is explored in this study. Electrostatic spray coating process is used to deposit the coating on the plasma-treated substrates for better adhesion. Ultra-high molecular weight polyethylene (UHMWPE) has been selected as the parent matrix for the coating due to its biocompatibility and excellent tribological properties. However, to improve its load-bearing capacity carbon nanotubes (CNT’s) (0.5, 1.5, and 3 wt.%) are used as reinforcement and to further enhance its performance, different weight percent of hydroxyapatite (HA) (0.5, 1.5, 3, and 5 wt.%) are introduced to form a hybrid nanocomposite coating. The dispersion of CNT’s and HA was evaluated by Raman spectroscopy and scanning electron microscopy. The electrochemical corrosion behavior of the nanocomposite coatings was evaluated by performing potentiodynamic polarization and electrochemical impedance spectroscopic tests in simulated body fluid. Tribological performance of the developed hybrid nanocomposite coating was evaluated using a 6.3 mm diameter stainless steel (440C) ball as the counterface in a ball-on-disk configuration. Tests were carried out at different normal loads (7 N, 9 N, 12 N, and 15 N) and a constant sliding velocity of 0.1 m/s. The developed hybrid nanocomposite coating showed excellent mechanical properties in terms of high hardness, improved scratch resistance, and excellent wear and corrosion resistance compared to the pristine UHMWPE coatings.


2015 ◽  
Vol 60 (3) ◽  
pp. 1865-1870
Author(s):  
J. Przondziono ◽  
E. Hadasik ◽  
W. Walke ◽  
J. Szala

Abstract The study presents the results of research into the impact of strain in cold drawing and surface modification treatment on corrosion properties of wires made of X10CrNi 18-8 steel used in maxillofacial surgery. Scanning microscopy enabled to make images of the surface of wires after drawing process as well as after surface modification treatment. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves in artificial saliva. In order to evaluate physical and chemical properties of the surface, electrochemical impedance spectroscopy was performed. Test results show deterioration of corrosion properties of wires along with strain taking place in drawing process. It was proved that electrochemical polishing and chemical passivation caused sudden increase of resistance of wires made of stainless steel to pitting corrosion in artificial saliva.


2013 ◽  
Vol 199 ◽  
pp. 412-417 ◽  
Author(s):  
Krzysztof Dudzik ◽  
Adam Charchalis

The results of corrosion properties research of aluminum alloy AW 7020 (AlZn5Mg1) welded by friction stir welding FSW were presented. Friction Stir Welding (FSW) a new technology can be successfully used for butt welding of different types of aluminum alloy sheets. In the article the parameters for friction stir welding of sheets made of AlZn5Mg1 (7020) alloy was presented. The study was carried out in accordance with the requirements of the ASTM G 106. EIS measurement was performed in three electrode system in an artificial seawater (3.5% NaCl). Impedance studies were carried out at the corrosion potential. Changed voltage signal amplitude in the range ± 10 mV and frequency range of changes was as follows: 100 kHz - 0.1 Hz. Atlas 0531 EU & IA potentiostat was used for studies. The results of electrochemical impedance spectroscopy are presented in the form of parameters characterizing the corrosion process. Obtained results were statistically analyzed. The electrochemical impedance spectroscopy studies have shown that the joint welded by FSW has better electrochemical corrosion resistance than the native material - AW-7020 alloy. Original value are received results of the corrosion properties of new method friction stir welded AlZn5Mg1 alloy compared with the native material.


2012 ◽  
Vol 189 ◽  
pp. 36-39
Author(s):  
Hai Jiao Yang ◽  
Sheng Tao Zhang ◽  
Lei Zhang

The corrosion behavior of copper in halide solutions was investigated by cyclic voltammetry, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). On this basis, the mechanism of electrochemical corrosion behavior of Cu in halide solutions has been analyzed. The study explores the corrosive effect of the halide ions on copper materials and provides a theoretical basis for the inhibition of halide ions on the corrosion of copper materials.


2018 ◽  
Vol 62 (2) ◽  
pp. 45-53 ◽  
Author(s):  
Kamil Borko ◽  
F. Pastorek ◽  
Jacková M. Neslušan ◽  
S. Fintová ◽  
B. Hadzima

Abstract The actual industrial trend is focused on weight reduction of constructions while preserving strength properties. For this purpose, conventional steel are replaced by high strength steels.. The aim of this study was to evaluate the effects of mechanical surface pre-treatment on corrosion resistance of high strength low alloy steel Domex 700 before and after surface treatment by manganese phosphating. Tested environment was 0,1M NaCl solution. Evaluation of mechanical pre-treatment and phosphating effects on corrosion resistance was realized by electrochemical measurements: potentiodynamic polarization measurements (Tafel analysis) and electrochemical impedance spectroscopy (equivalent circuits). From resulsts it is possible to conclude, that creation of manganese phosphate layer on ground and shot peened steel surface significantly increases the corrosion resistance of Domex 700 steel.


2019 ◽  
Vol 272 ◽  
pp. 01001
Author(s):  
Nadia HAMMOUDA ◽  
Kamel BELMOKRE

The purpose of the different operations under the term surface preparation is to get a clean surface able to be coated. It is essential to adapt this preparation in terms of the metallurgical nature of the substrate, cleanliness, its shape and roughness. Surface preparations especially the operations of sandblasting, polishing, or grinding prove of capital importance. It allows to modify the superficial properties of these materials, after these treatments the surface becomes very active. This paper evaluates the mechanical surface treatments effect by sandblasting (Sa 1.5 and Sa 2.5) on the electrochemical corrosion characteristics of C-1020 carbon steel in 3% NaCl solution electrolyte simulating aggressive sea atmosphere. Investigations are conducted using stationary (free potential "E-t, polarization curves "E-i", the Tafel rights and the Rp) and nonstationary electrochemical tools such as electrochemical impedance. The results obtained allowed us to highlight that sandblasted carbon steel degrades with immersion time because of the roughness of the surface. These results were confirmed by the plot of the electrochemical impedance diagrams, confirming that the process governing kinetics is under charge transfer control. Good protection against corrosion cannot be obtained only with a good surface preparation of the adapted steel.


2020 ◽  
Vol 67 (5) ◽  
pp. 465-472
Author(s):  
Wei Luo ◽  
Lei Hu ◽  
Yimin Xv ◽  
Jian Zhou ◽  
Wentao Xv ◽  
...  

Purpose This paper aims to focus on an assessment of the electrochemical corrosion performance of bulk NC copper in a variety of corrosion environments. Design/methodology/approach The electrochemical corrosion behavior of bulk nanocrystalline (NC) copper prepared by inert gas condensation and in situ warm compress technique was studied by using potentiodynamic polarization and electrochemical impedance spectroscopy tests in de-aerated 0.1 M NaOH solution. Findings NC copper exhibited a typical active-passive-transpassive behavior with the formation of duplex passive films, which was qualitatively similar to coarse-grain (CG) copper. Although a compact passive film formed on NC copper surface, the corrosion resistance of NC copper was lower in comparison with CG copper. The increase in corrosion rate for NC copper was mainly attributed to the high activity of surface atoms and intergranular atoms. These atoms led to an enhancement of passive ability and an increase of dissolution rate of passive film in oxygen-deficiency solution. For NC copper, the corrosion resistance decreased as grain size increased in NC range. Originality/value The difference in corrosion resistance between bulk NC copper and its CG counterpart is dependent upon the corrosion solution. In a previous work, the potentiodynamic polarization tests revealed that NC copper bulks (grain size 48, 68, 92 nm) had identical corrosion resistance to CG copper bulk in naturally aerated 0.1 M NaOH solution. The results might be related to the dissolved oxygen in the medium.


2016 ◽  
Vol 60 (4) ◽  
pp. 107-113 ◽  
Author(s):  
F. Pastorek ◽  
K. Borko ◽  
S. Dundeková ◽  
S. Fintová ◽  
B. Hadzima

Abstract Large number of mechanical and chemical surface pretreatment techniques is actually used on steels in industrial practice. Choosing the right combination of these technologies is one of the most important tasks for many applications. The purpose of this research was to evaluate the influence of selected mechanical surface preparation methods (grinding, sandblasting) on the quality and electrochemical corrosion characteristics of S355J2 steel before and after the final chemical surface treatment by the technology of manganese phosphating. The surface morphology of the formed phosphate layer was evaluated by a scanning electron microscopy (SEM) and the cross section analysis was performed by a light metallographic microscopy. 0.1M Na2SO4 solution simulating aggressive industrial pollution was selected for electrochemical corrosion tests. Impact evaluation of various mechanical and chemical surface treatments on the corrosion properties of the tested steel was realized by potentiodynamic polarization tests (PD) and electrochemical impedance spectroscopy (EIS) using the Tafel analysis and equivalent circuits method respectively. The obtained results proved that sandblasting negatively affected the corrosion resistance of S355J2 steel and subsequently created manganese phosphate layer.


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