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.

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.

Simulating the Temper Rolling of Galvanized Steel

2005 ◽  
Vol 105 ◽  
pp. 371-378 ◽  
Author(s):  
G. Vincent ◽  
C. Counhaye ◽  
Claude Esling
Keyword(s):  
Numerical Simulation ◽  
Rolling Process ◽  
Galvanized Steel ◽  
Stress Fields ◽  
Temper Rolling ◽  
Coated Steel ◽  
Steel Sheets ◽  
Skin Pass ◽  
Early Results ◽  
Zinc Coated Steel

This work deals with early results obtained in numerical simulation of the skin-pass of zinc coated steel sheets. First, the streamline model and its adaptation to the case of the temper rolling of coated steel sheets are detailed. Second, the influence of various parameters of the rolling process on the strain and stress fields in the sheet is numerically calculated.

Local Mechanical Properties of Zinc-Iron Coated Steel Sheets by Depth-Sensing Indentation

2018 ◽  
Vol 784 ◽  
pp. 153-158
Author(s):  
Ľubomír Ambriško ◽  
Ladislav Pešek
Keyword(s):  
Mechanical Properties ◽  
Iron Concentration ◽  
Intermetallic Phases ◽  
Coated Steel ◽  
If Steel ◽  
Depth Sensing ◽  
Steel Sheets ◽  
Coating Surface ◽  
Annealing Conditions ◽  
Coating Composition

Depth-sensing indentation (DSI) is used in this work to determine the change of local mechanical properties by annealing of hot-dip galvanized IF steel sheets. The influence of annealing conditions (temperature and time) on: (i) coating composition; (ii) local mechanical properties and (iii) roughness of the coating surface was quantified. Annealing of steel samples (Ti-IF steel and Ti-Nb-P-IF steel alloyed with phosphorus) was performed with different holding times (10, 60, and 300 s) by both temperatures 450 and 550 °C. The zinc in coating transformed during annealing to the intermetallic phases ZnxFey. Annealed Zn-Fe coatings, wherein the iron concentration falls towards the surface, consist of different intermetallic phases.

Effectiveness of Stamping Lubricants in Erichsen Test

2013 ◽  
Vol 549 ◽  
pp. 325-332
Author(s):  
Bora Şener ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Low Carbon Steel ◽  
Galvanized Steel ◽  
Interstitial Free ◽  
Low Carbon ◽  
Normal Anisotropy ◽  
Punch Force ◽  
Steel Sheets ◽  
Effective Lubricant ◽  
Erichsen Test

In the present work, formability of ultra low carbon steel sheets (uncoated interstitial free and galvanized steel sheet) has been characterized and the effectiveness of dry and liquid lubricants on formability of these steel sheets was evaluated by using the standard Erichsen test. Primarily, some important mechanical properties of materials like strain hardening coefficient (n), normal anisotropy (r) were determined using the tensile test and formability of these steel sheets has been correlated with these mechanical properties. Then these steel sheets were subjected to the Erichsen test using four different lubricants. Teflon, PVC, Polyethylene films and mineral oil were used in the experiments. Finite element simulations were done using various friction coefficients. Erichsen tests were conducted at 1 kN blank holder force and 2.4 mm/min punch velocity. Values of the Erichsen index and punch force-displacement curves were determined for each lubricant. PVC film proved to be the most effective lubricant for both materials.

Characterization of a Chromium-Free Passivation Coating on Hot Dip Al-Zn Allay Coated Steel Sheets

2013 ◽  
Vol 634-638 ◽  
pp. 2931-2934
Author(s):  
Ping Yuan
Keyword(s):  
Salt Spray ◽  
Optical Emission ◽  
Acrylic Resin ◽  
Organic Coating ◽  
Neutral Salt ◽  
Coated Steel ◽  
Corrosion Performance ◽  
Steel Sheets ◽  
Coated Steel Sheet ◽  
Passivation Coating

The hot dip Al-Zn alloy coated steel sheet was passivated with chromium-free passivation solution which adopted the molybdate and acrylic resin as the main film-forming substances. The surface morphology and corrosion performance of the coating were studied experimentally by using glow discharge optical emission spectroscopy(GD-OES), scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDS), polarization curves and the neutral salt spray test. The GD-OES and SEM results show that the molybdate-containing thin organic coating is deposited on the substrate compactly and homogeneously without obvious tiny cracks. The test results of corrosion performance show that the corrosion potential and current density of the passive films decrease obviously in comparison with those of the substrate, and the corrosion resistance of the coating is comparable with that of the chromate passivation coating.

scholarly journals Disk Laser Welding of Car Body Zinc Coated Steel Sheets / Spawanie Laserem Dyskowym Blach Ze Stali Karoseryjnej Ocynkowanej

2015 ◽  
Vol 60 (4) ◽  
pp. 2913-2922 ◽  
Author(s):  
A. Lisiecki ◽  
R. Burdzik ◽  
G. Siwiec ◽  
Ł. Konieczny ◽  
J. Warczek ◽  
...  
Keyword(s):  
Laser Welding ◽  
Mechanical Performance ◽  
Galvanized Steel ◽  
Coated Steel ◽  
Butt Joints ◽  
Beam Spot ◽  
Disk Laser ◽  
Car Body ◽  
Steel Sheets ◽  
Zinc Coated Steel

Autogenous laser welding of 0.8 mm thick butt joints of car body electro-galvanized steel sheet DC04 was investigated. The Yb:YAG disk laser TruDisk 3302 with the beam spot diameter of 200 μm was used. The effect of laser welding parameters and technological conditions on weld shape, penetration depth, process stability, microstructure and mechanical performance was determined. It was found that the laser beam spot focused on the top surface of a butt joint tends to pass through the gap, especially in the low range of heat input and high welding speed. All test welds were welded at a keyhole mode, and the weld metal was free of porosity. Thus, the keyhole laser welding of zinc coated steel sheets in butt configuration provides excellent conditions to escape for zinc vapours, with no risk of porosity. Microstructure, microhardness and mechanical performance of the butt joints depend on laser welding conditions thus cooling rate and cooling times. The shortest cooling time t8/5 was calculated for 0.29 s.

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