Synergistic Corrosion Resistance of Cerium Film and Silane Film on Hot-Dip Galvanized Steel

2010 ◽  
Vol 34-35 ◽  
pp. 2021-2025
Author(s):  
Hai Jiang Wu ◽  
Fei Ying Yang
Keyword(s):  
Corrosion Resistance ◽  
Double Layer ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Protection Efficiency ◽  
Protection Effect ◽  
Steel Sheets ◽  
Environmental Friendly ◽  
Zinc Corrosion ◽  
Silane Solution

This work aims at developing a new environmental-friendly treatment for hot-dip galvanized (HDG) steel as alternative to the classic systems based on chromates. A double layer film on the HDG steel sheets was prepared by immersing the sheets in 5 g/L Ce(NO3)3 aqueous solution and 5 vol.% silane solution in turn. The morphology of the cerium conversion film was analyzed using scanning electron microscopy (SEM). The corrosion resistance of the films was investigated by linear polarization (LPR) and natural salt spray (NSS) tests. The results show that the surface morphology of cerium conversion film appears on a “dry-mud” structure, which is favorable to enhance the combined strength between the cerium conversion and the silane film. The corrosion protection efficiency of the double layer films increases greatly, especially both the anodic and cathodic processes of zinc corrosion on the samples are suppressed conspicuously, and the synergistic protection effect of the single cerium film and the single silane film is evident.

The Influence of Major Defects on the Properties of Continuous Galvanized Steel Sheet

2012 ◽  
Vol 445 ◽  
pp. 661-666 ◽  
Author(s):  
A. Azimi ◽  
F. Shahriari ◽  
F. Ashrafizadeh ◽  
M.R. Toroghinezhad ◽  
J. Jamshidi
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Tensile Test ◽  
Steel Sheet ◽  
Corrosion Behaviour ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Tafel Polarization ◽  
Steel Sheets ◽  
Bare Spot

Production of defect-free galvanized steel sheet is considered a major concern for automotive and other critical applications; nevertheless, the occurrence of some defects in the coated sheets is unavoidable. In order to alleviate the problem, we need to know the extent to which the properties of a galvanized sheet are influenced by the presence of a given defect. In this investigation, specimens including any of the two major defects of continuously galvanized steel sheets were selected from a large number of coated samples. The defects, including furnace roll pimples and bare spots, were microstructurally characterized and their influence on corrosion behaviour and mechanical properties of the steel sheet was evaluated. Corrosion resistance was examined via standard salt spray test and Tafel polarization. Tensile test was employed as a measure of mechanical properties of the defective galvanized sheets. The results indicated that the presence of defects had little influence on the tensile properties of the samples, but considerably reduced their corrosion resistance. Based on the results of salt spray tests, pimples reduced corrosion resistance of galvanized sheets 23 % (50 hours) on average and bare spot defects caused reduction in corrosion resistance up to 39%.

scholarly journals Mechanical clinching and self-pierce riveting for sheet combination of 780-MPa high-strength steel and aluminium alloy A5052 sheets and durability on salt spray test of joints

2021 ◽  
Vol 113 (1-2) ◽  
pp. 59-72
Author(s):  
Yohei Abe ◽  
Ken-ichiro Mori
Keyword(s):  
Aluminium Alloy ◽  
High Strength Steel ◽  
Salt Spray ◽  
High Strength ◽  
Alloy Sheet ◽  
Galvanized Steel ◽  
Load Reduction ◽  
Minimum Thickness ◽  
Steel Sheets ◽  
Mechanical Clinching

AbstractTo increase the usage of high-strength steel and aluminium alloy sheets for lightweight automobile body panels, the joinability of sheet combinations including a 780-MPa high-strength steel and an aluminium alloy A5052 sheets by mechanical clinching and self-pierce riveting was investigated for different tool shapes in an experiment. All the sheet combinations except for the two steel sheets by self-pierce riveting, i.e., the two steel sheets, the two aluminium alloy sheets, and the steel-aluminium alloy sheets, were successfully joined by both the joining methods without the gaps among the rivet and the sheets. Then, to show the durability of the joined sheets, the corrosion behaviour and the joint strength of the aged sheets by a salt spray test were measured. The corrosion and the load reduction of the clinched and the riveted two aluminium alloy sheets were little. The corrosion of the clinched two steel sheets without the galvanized layer progressed, and then the load after 1176 h decreased by 85%. In the clinched two galvanized steel sheets, the corrosion progress slowed down by 24%. In the clinched steel and aluminium alloy sheets, the thickness reduction occurred near the minimum thickness of the upper sheet and in the upper surface on the edge of the lower aluminium alloy sheet, whereas the top surface of the upper sheet and the upper surface of the lower sheet were mainly corroded in the riveted joint. The load reduction was caused by the two thickness reductions, i.e., the reduction in the minimum thickness of the upper sheet and the reduction in the flange of the aluminium alloy sheet. Although the load of the clinched steel without the galvanized coating layer and aluminium alloy sheets decreased by about 20%, the use of the galvanized steel sheet brought the decrease by about 11%. It was found that the use of the galvanized steel sheets is effective for the decrease of strength reduction due to corrosion.

scholarly journals Effects of Fe-P Upper Layer Coating Weight on Paintability and Corrosion Resistance of Double Layer Alloy Coated Steel Sheets

1986 ◽  
Vol 72 (8) ◽  
pp. 976-983 ◽  
Author(s):  
Toru HONJO ◽  
Kazuaki KYONO ◽  
Koji YAMATO ◽  
Toshio ICHIDA ◽  
Toshio IRIE
Keyword(s):  
Corrosion Resistance ◽  
Double Layer ◽  
Coated Steel ◽  
Steel Sheets ◽  
Coating Weight ◽  
Layer Coating

Properties Study of Mixed Silane Films on the Surface of Steel

2014 ◽  
Vol 971-973 ◽  
pp. 135-138
Author(s):  
Zhen Dong Sun ◽  
Yan Ning Yang ◽  
Qing Peng Li ◽  
Jian Guo Liu ◽  
Chuan Wei Yan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Salt Spray ◽  
Adhesive Property ◽  
Epoxy Coating ◽  
Chemical Compositions ◽  
Neutral Salt ◽  
X Ray ◽  
Steel Sheets ◽  
Silane Solution ◽  
Scanning Electron

The mixed silane films were obtained on the surface of the Q235 steel sheets by directly immersing in a mixed silane solution containing γ-Glycidoxypropyltriethoxysilane (γ-GPS) and 1, 2-bis (triethoxysilyl) ethane (BTSE), The chemical compositions and microstructures of the films were examined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared spectroscopy (FTIR).The corrosion resistances were investigated by electrochemical measurements and neutral salt spray (NSS) test. The effects of silane films to the epoxy coating were investigated through the adhesive property test. The results showed that the γ-GPS/BTSE mixed silane film could remarkably improve the corrosion resistance of epoxy coating and prolong its service life.

Structural Properties of Zinc and ZnMgAl Coatings on Steel Sheets

2014 ◽  
Vol 782 ◽  
pp. 623-626 ◽  
Author(s):  
Mária Kollárová ◽  
Lucia Hrabčáková ◽  
Juraj Graban ◽  
Marta Šohajová
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Neutral Salt ◽  
Coating Structure ◽  
Properties Of Coatings ◽  
Steel Sheets ◽  
Mutual Comparison ◽  
Excellent Adhesion ◽  
Interdendritic Phase ◽  
Zinc Coatings

In the paper mutual comparison of zinc coatings enriched with small additions of Mg and Al (up to 1 wt.% Mg and 1 wt.% Al) and traditional zinc coatings produced by hot dip galvanizing, concerning some important properties of coatings like coating structure, cracks formation after deformation and corrosion resistance of deformed samples was studied. It was shown, that while traditional hot-dip zinc coatings are formed by homogenous zinc layer, exhibiting only low amount of soluble aluminium, coatings enriched by small amounts of Mg and Al, namely 0.6% Mg and 0.8% Al are formed by dendritic zinc matrix and interdendritic phase containing Zn-Mg-Al eutectics. Development of cracks was investigated in the area of maximal deformation of the samples subjected to stretching. It was found, that while traditional zinc coatings showed sporadic long fine cracks, zinc coatings enriched with Mg and Al exhibited aggregation of short thick cracks in the deformed area. Samples of both materials after stretching were also exposed in neutral salt spray atmosphere in corrosion chamber. It can be concluded, that material with coatings enriched with Mg and Al showed better results in corrosion tests contrary to the presence of massive cracks in the coating. This significantly increased corrosion resistance is possible due to excellent adhesion of zinc coatings, containing Mg and Al on drawing steels.

scholarly journals Effect of Inorganic Filler Addition on Non-Combustible and Mechanical Properties of Color Coated Steel Sheets

2020 ◽  
Vol 58 (11) ◽  
pp. 768-775
Author(s):  
Moon-Hi Hong ◽  
In-kyu Kim ◽  
Hye-Jeong Yun
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Inorganic Filler ◽  
Coated Steel ◽  
Coating Materials ◽  
Steel Sheets ◽  
Glow Discharge Spectroscopy ◽  
Coated Layer

Recent large-scale fires in buildings and logistic warehouses have become a major social issue, involving both property loss and multiple casualties. To make color coated steel sheets non-combustible and/or have anti-fire properties, various ways of optimizing manufacturing parameters have been investigated for outer, inner, roof and ceiling panels. In the present study, the effect of inorganic filler content and size on the non-combustible and mechanical properties of color coated steel sheets has been investigated using samples prepared as pre-painted coating materials. Both salt spray corrosion and chemical resistance tests were also carried out. Filler distribution and size were measured by optical microscopy, scanning electron microscopy and glow discharge spectroscopy, and found to be critical factors affecting non-combustible performance. As the amount of added filler increased, the non-combustible property of the color coated steel sheets improved, while mechanical properties, corrosion resistance by salt spray and chemical resistances deteriorated. During 3t-bending tests, the adhesive strength at the interface between coated layer and hot dip galvanized steel sheets was rather strong, although the filler-added upper coated layer was mostly peeled off. The mechanical properties of 30% filler addition samples were compared to samples with less than 20% filler addition. The main reason for the poorer performance was clarified in terms of filler size and crack propagation in the 3t-bended color coated layer.

Abrasion Resistance and Corrosion Resistance of Chromium-Free Fingerprint-Resistant Zn and Zn-Al-Mg Coating Cold-Rolled Steel Sheets

2021 ◽  
Vol 1035 ◽  
pp. 545-553
Author(s):  
Yan Huang ◽  
Ren Bo Song ◽  
Huan Jun Wei ◽  
Zhe Rui Zhang ◽  
Li Fang Yang
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Zinc Coating ◽  
Neutral Salt ◽  
Rolled Steel ◽  
Pure Zinc ◽  
Cold Rolled Steel ◽  
Steel Sheets ◽  
Long Time ◽  
Cold Rolled

The wear resistance and corrosion resistance of chromium-free fingerprint-resistant pure zinc and Zn-Al-Mg coated cold-rolled steel sheets were studied by micro-friction wear experiments and neutral salt spray experiments. Two products are worn for a long time with a large load (5N load, 50 times abrasion), the depth of wear zone of Zn-Al-Mg coating product is 9% shallower than that of pure zinc coating product, and the width of wear zone is 15.4% smaller. Both products still meet the requirements of use after corrosion. The corrosion resistance of two products after degreasing treatment was significantly reduced. The Mg and Al in the Zn-Al-Mg coating can hinder the progress of corrosion, so it has better corrosion resistance.

Passivation Effect of Rare Earth Lanthanum on Galvanized Steel

2014 ◽  
Vol 525 ◽  
pp. 31-34
Author(s):  
Xiao Feng Liu
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Electrochemical Impedance ◽  
Orthogonal Experiment ◽  
Salt Spray ◽  
Conversion Coating ◽  
Galvanized Steel ◽  
Neutral Salt ◽  
White Rust ◽  
Order Of Magnitude

By way of chemical marinate method, carrying out rare earth lanthanum to corrosion protect galvanized steel. The process of rare earth lanthanum conversion coating for galvanized steel was studied by using orthogonal experiment to get the optimized passivation parameters when the concentration of La (NO3) is 30g/L, H2O2is 20ml/L, pH=4 and was passivated at 40°C for 30s. The corrosion resistance was examined by weight loss tests, neutral salt spray tests (NSS) and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion impedance of the pretreated sample was significantly improved, the corrosion rate was decreased by one order of magnitude, and the anti-white rust time was 54h.

Chromate-Free Passive Films Made by Manganate and Waterborne Polyurethane on Galvanized Steel Sheets

2010 ◽  
Vol 154-155 ◽  
pp. 292-298
Author(s):  
Xiang Hua Kong ◽  
Hui Yang ◽  
Ya Xuan Liu ◽  
Wan Heng Lu ◽  
Jing Guo ◽  
...  
Keyword(s):  
Steel Sheet ◽  
Waterborne Polyurethane ◽  
Passive Films ◽  
Galvanized Steel ◽  
Sem Observation ◽  
Steel Sheets ◽  
Environmental Friendly ◽  
Xrd Patterns ◽  
Steel Substrates

In order to develop an environmental friendly passive films on galvanized steel sheet, a chromium-free passive solution based on waterborne polyurethane (WPU) and Manganate was studied. The results show that the optimized compositions in passive solution are KMnO4 6g/L, (NH2)2CS 5g/L and WPU 150g/L. The passive films were prepared by dipping steel substrates into the passive solution for 10 seconds and drying at 120 °C for 30 seconds. SEM observation shows that the film’s thickness is about 1.5 µm. XRD patterns indicates that the chromate-free passive films mainly consisted of MnO2 and K2MnO4. Anticorrosion tests indicate that the chromate-free passive films can provide an excellent barrier to corrosive agents.

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