Electrolytic accelerated corrosion morphology for structural steel based on an improved solution

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qi Si ◽  
Yang Ding ◽  
Liang Zong
Keyword(s):  
Structural Steel ◽  
Atmospheric Corrosion ◽  
Fractal Theory ◽  
Salt Spray ◽  
Neutral Salt ◽  
Mixed Solution ◽  
Corrosion Morphology ◽  
Accelerated Corrosion ◽  
Electrolytic Corrosion ◽  
Surface Morphologies

Abstract Atmospheric corrosion degrades the mechanical properties of steel structures mainly because of stress concentrations caused by an uneven corrosion topography. Electrolytic corrosion is regarded as one of the most efficient indoor accelerated corrosion approaches, while, the uneven atmospheric corrosion topography usually cannot be well simulated by electrolytic corrosion. This study aims to introduce an electrolytic corrosion solution suitable for simulating atmospheric corrosion. The surface morphologies of the structural steel specimens after electrolytic corrosion in three different solutions under various electrification time and magnitude of the current were compared. The surface characteristics of the corroded steel plates were measured by a 3D noncontact surface topography scanner, and analyzed based on surface roughness theory and fractal theory. The results showed that the mixed solution of 0.5% CH3COONa and 0.2% NaCl will produce pitting corrosion on the steel surface, and the surface morphologies of the steel specimens after electrolytic corrosion were consistent with that of neutral salt spray accelerated corrosion test. It is verified that the electrolytic accelerated corrosion in such a solution can simulate actual atmospheric corrosion reasonably.

scholarly journals Accelerated cyclic corrosion tests

2016 ◽  
Vol 60 (2) ◽  
pp. 46-49
Author(s):  
T. Prošek
Keyword(s):  
Quality Control ◽  
Residual Life ◽  
Material Selection ◽  
Salt Spray ◽  
Life Time ◽  
Poor Correlation ◽  
Neutral Salt ◽  
Accelerated Corrosion ◽  
Corrosion Tests ◽  
Accelerated Corrosion Tests

Abstract Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

ANTICORROSION PROPERTIES OF Zn–Al–Mg–ZnO COMPOSITE COATING PREPARED BY COLD SPRAYING

2020 ◽  
Vol 27 (09) ◽  
pp. 1950211
Author(s):  
XINQIANG LU ◽  
SHOUREN WANG ◽  
TIANYING XIONG ◽  
DAOSHENG WEN ◽  
GAOQI WANG ◽  
...  
Keyword(s):  
Raw Materials ◽  
Composite Coatings ◽  
Salt Spray ◽  
Wear Test ◽  
Cold Spraying ◽  
Oxidation Products ◽  
Steel Matrix ◽  
Neutral Salt ◽  
Electrochemical Protection ◽  
Accelerated Corrosion

Two kinds of composite coatings, Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text], were prepared on steel matrix (Q235) by cold spraying. The Zn, Al, Mg, and ZnO in raw materials were calculated by percentage of mass. The morphology of the original coating was observed by scanning electron microscopy (SEM) and characterized by energy dispersive spectroscopy (EDS). It was found that the microstructures of Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] composite coatings prepared by cold spraying were compact without oxidation products, and the plastic deformation of powder particles was significant. The friction and wear test data of the two coatings showed that the Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] coating had longer-lasting protective properties and wear resistance under the same conditions. Neutral salt spray test (NSS) and electrochemical accelerated corrosion test were carried out on samples at different time periods. The results of samples’ corrosion microstructure and electrochemical curves showed that Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] have good electrochemical protection performance, and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] coating has better protection effect.

Salt Spray Corrosion Performance Associated with the Glass Forming Ability of the FeCo-Based Bulk Metallic Glasses

2014 ◽  
Vol 618 ◽  
pp. 109-113
Author(s):  
Wei Jiang ◽  
Qing Jun Chen ◽  
Jun Shen ◽  
Fa Bi Zhang ◽  
Xian Liang Zhou ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Metallic Glasses ◽  
Salt Spray ◽  
Bulk Metallic Glasses ◽  
Glass Forming Ability ◽  
Neutral Salt ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Salt Spray Corrosion ◽  
Glass Forming

For the bulk amorphous Fe24+xCo24-xCr15Mo14C15B6Y2(X=0, 2, 4, 6 and 17) alloy, the corresponding corrosion properties associated with glass forming ability (GFA) have been carried out. Neutral salt spray corrosion test results show that the Fe28Co20Cr15Mo14C15B6Y2 alloy has the minimum corrosion rate, followed by Fe26Co22Cr15Mo14C15B6Y2, Fe24Co24Cr15Mo14C15B6Y2, Fe30Co18Cr15Mo14C15B6Y2, Fe41Co7Cr15Mo14C15B6Y2 and Ti6Al4V alloys. Specifically, the Fe28Co20Cr15Mo14C15B6Y2 alloy with the highest GFA also has the best corrosion resistance. With the increasing of Co addition, the corrosion resistance of the FeCo-based bulk metallic glasses is first increases and then decreases, which has the same trend of GFA with the change of Co elements. Furthermore, corrosion morphology are different for FeCo-based BMGs with different Co content.

scholarly journals A Novel Accelerated Corrosion Test for Supporting Devices in a Floating Photovoltaic System

2021 ◽  
Vol 11 (8) ◽  
pp. 3308
Author(s):  
Chun-Kuo Liu ◽  
Zhong-Ri Kong ◽  
Ming-Je Kao ◽  
Teng-Chun Wu
Keyword(s):  
Corrosion Test ◽  
Salt Spray ◽  
Protective Layer ◽  
Photovoltaic System ◽  
Galvanized Steel ◽  
Neutral Salt ◽  
Accelerated Corrosion ◽  
Accelerated Corrosion Test ◽  
Type 304

Recently, countries from around the globe have been actively developing a new solar power system, namely, the floating photovoltaic (FPV) system. FPV is advantageous in terms of efficiency and cost effectiveness; however, environmental conditions on the surface of water are harsher than on the ground, and the regulations and standards for the long-term durability of supporting devices are insufficient. As a result, this study aims to investigate the durability of supporting devices through a novel type of accelerated corrosion test, copper-accelerated acetic acid salt spray (CASS). After an eight-day CASS test, the results demonstrated that only a small area of white protective layer on the SUPERDYMA shape steel was fully corroded and rusted. Moreover, five types of screw, fastened solidly on the SUPERDYMA shape steel, namely a galvanized steel screw capped with a type 316 stainless steel (SS) nut, a type 304 SS screw, a type 410 SS screw, a chromate-passivated galvanized steel screw, and a XP zinc–tin alloy coated steel screw, achieved varying degrees of rust. In general, the corrosion degree of the eight-day CASS test was more serious than that of the 136-day neutral salt spray (NSS) test. Therefore, the CASS test is faster and more efficient for the evaluation of the durability of supporting devices.

scholarly journals Pore resistance limitations from EIS data for the evaluation of organic DTM coatings based on a self-crosslinking acrylic resin

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
M. Vanegas ◽  
J.J Medina ◽  
L.F. Vesga ◽  
W. Bejarano
Keyword(s):  
Atmospheric Corrosion ◽  
Visual Inspection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Acrylic Resin ◽  
Point Of View ◽  
Neutral Salt ◽  
Crosslinking Process ◽  
Acrylic Resins ◽  
Coated Surfaces

Self-crosslinking Water-based acrylic resins are currently widely used in the formulation of paints for the protection of materials exposed to atmospheric corrosion. These resins, given their "self-crosslinking" designation, initiate their crosslinking process once they are applied on a previously prepared surface. It is expected that with time they will increase their protection, due to their continuing self-crosslinking mechanism. In this work, metallic plates coated with these resins were evaluated under simulated salt neutral spray (ASTM B117). The coating degradation processes were monitored by Electrochemical Impedance Spectroscopy (EIS) and visual inspection, according to ASTM D610 and ASTM D714, aiming to identify and quantify the appearance of blistering and corrosion products. The results revealed rapid drops in pore resistance (Rpo) for systems exposed to neutral salt spray (NSS), saline-acidic or acidified conditions, which coincided with the formation of blisters. On the contrary, the systems in the wet chamber showed an increase in the Rpo, which evidences from an electrical point of view a greater opposition to the passage of current. Notwithstanding, still the appearance of blisters on the coated surfaces was observed.

scholarly journals Anticorrosion Properties of Zn–Al Composite Coating Prepared by Cold Spraying

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 210 ◽  
Author(s):  
Xinqiang Lu ◽  
Shouren Wang ◽  
Tianying Xiong ◽  
Daosheng Wen ◽  
Gaoqi Wang ◽  
...  
Keyword(s):  
Composite Coating ◽  
Energy Dispersive Spectrometer ◽  
Salt Spray ◽  
Cold Spraying ◽  
Alloy Coating ◽  
Raw Material ◽  
Neutral Salt ◽  
Accelerated Corrosion ◽  
Al Composite ◽  
Strong Adhesion

In order to slow down the corrosion and wear of offshore equipment, the Zn–Al composite coating was prepared on Q345 substrate by cold spray technique. The mass fraction of Zn and Al in the raw material was 2:3. The microstructure of the original coating was observed by scanning electron microscopy (SEM) and was characterized by energy dispersive spectrometer (EDS). From the composite alloy coating obtained by cold spraying, it was observed that the Zn and Al particles were uniformly distributed without oxidation product, and the powder particles were significantly plastically deformed. The microstructure of the composite coating is very dense and has strong adhesion to the substrate. Neutral salt spray test (NSS) and electrochemical accelerated corrosion test results showed that Zn–Al composite coating can effectively provide corrosion protection.

Effects of Deformation on Atmospheric Corrosion of Galvanized Steel

2006 ◽  
Vol 510-511 ◽  
pp. 1134-1137
Author(s):  
Jae Woong Choi ◽  
Gil Ho Hwang ◽  
Hong Rae Cha ◽  
Sung Goon Kang
Keyword(s):  
Relative Humidity ◽  
Corrosion Test ◽  
Atmospheric Corrosion ◽  
Surface Damage ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Accelerated Corrosion ◽  
Corrosion Rates ◽  
Accelerated Corrosion Test ◽  
Surface Morphologies

The effects of deformation on corrosion behavior of galvanized steel were investigated. Accelerated corrosion test was conducted under the conditions of 30oC and 90% relative humidity with flowing 200ppm sulfur dioxide gas for five weeks. Surface morphologies and corrosion products were analyzed by SEM/EDS and XRD. The corrosion products were composed of hydrates of ZnSO4. And corrosion rates of each part, bottom, bended and wall, were increased with growing strain due to surface damage and enlargement of naked surface for corrosion.

scholarly journals Accelerated Corrosion Tests in Quality Labels for Powder Coatings on Galvanized Steel—Comparison of Requirements and Experimental Evaluation

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6547
Author(s):  
Izabela Kunce ◽  
Agnieszka Królikowska ◽  
Leszek Komorowski
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Experimental Evaluation ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Neutral Salt ◽  
Powder Coatings ◽  
Accelerated Corrosion ◽  
Corrosion Tests ◽  
Accelerated Corrosion Tests

Powder coatings are widely applied for corrosion protection of steel, aluminum, and hot dip galvanized steel in a variety of corrosive environments. Powder coatings are subjected to a number of strict laboratory tests to determine their mechanical properties, corrosion resistance, and color stability. Among European quality certificates for powder coatings applied to galvanized steel, the most commonly recognized are GSB-ST and Qualisteelcoat certificates, which also refer to the EN 13438 standard. Certificates of quality for powder coatings are constantly updated according to the latest research results and experience of specialists operating in the field of corrosion protection. This paper presents an experimental evaluation of how the required length of selected accelerated corrosion tests can affect the final assessment of powder coatings. On the example of two powder painting systems: polyester as well as based on epoxy and polyester resins, the paper presents the influence of the time of accelerated corrosion tests: ISO 6270, ISO 9227 (Neutral Salt Spray and Acetic Acid Salt Spray), and ISO 3231 on the protective properties of the coatings. The results of damage assessment according to ISO 4628 have been correlated with the requirements of particular quality specifications. Additionally, based on FTIR (Fourier Transform Infrared Spectroscopy) and EIS (Electrochemical Impedance Spectroscopy) analyses, the influence of the applied corrosion tests on the degradation degree of the coatings studied has been presented. The paper aims to present a tests for those powder coating systems applied to facilities for which the main requirement is corrosion resistance rather than aesthetics.

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