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Based on the advantages of conventional hot-dip galvanizing made from quasi-pure zinc melts in the event of fire, this article aims to perform a series of tests to verify whether a similar effect can be achieved with zinc-aluminum coatings.

The emissivity of galvanized surfaces, which were applied to steel specimens by the batch hot-dip galvanizing process, was experimentally determined under continuously increasing temperature load. In addition to a quasi-pure zinc melt serving as a reference, a zinc melt alloyed with 500 ppm aluminum and thin-film galvanized with a melt of zinc and 5% aluminum were used. For the latter, variants of post-treatment measures in terms of a passivation and sealing of the galvanizing were also investigated.

The results show that lower emissivity can be achieved at higher temperatures by adding aluminum to the zinc melt and thereby into the zinc coating. The design values required for the structural fire design were proposed, and an exemplary calculation of the temperature development in the case of fire was carried out based on the values. The result of this calculation indicates that the savings potential becomes apparent, when using zinc-aluminum coatings.

The presented novel tests describe the behavior of zinc-aluminum coatings under the influence of elevated temperatures and their positive effect on the emissivity of steel components galvanized by this method. The results provide valuable insights and information on the performance in the event of fire and the associated potential savings for steel construction.

This article aims to focus on implementing Lean Six Sigma (LSS) in steel manufacturing to enhance productivity and quality in the galvanizing process line. In recent trends, manufacturing organizations have expressed strong interest in the LSS since they attempt to enhance its overall operations without imposing significant financial burdens.

This article used lean tools and Six Sigma's DMAIC (Define, Measure, Analyze, Improve and Control) with Yin's case study approach. This study tried to implement the LSS for the steel galvanizing process in order to reduce the number of defects using various LSS tools, including 5S, Value stream map (VSM), Pareto chart, cause and effect diagram, Design of experiments (DoE).

Results revealed a significant reduction in nonvalue-added time in the process, which led to improved productivity and Process cycle efficiency (PCE) attributed to applying lean-Kaizen techniques. By deploying the LSS, the overall PCE improved from 22% to 62%, and lead time was reduced from 1,347 min to 501 min. DoE results showed that the optimum process parameter levels decreased defects per unit steel sheet.

This research demonstrated how successful LSS implementation eliminates waste, improves process performance and accomplishes operational distinction in steel manufacturing.

Since low-cost/high-effect improvement initiatives have not been adequately presented, further research studies on adopting LSS in manufacturing sectors are needed. The cost-effective method of process improvement can be considered as an innovation.

Hot Dip Galvanizing is used extensively throughout industry to protect steel products from environmental corrosion. However, the process of lowering the work into the galvanizing bath, then completely immersing it and finally withdrawing it produces emissions of fine particulate pollutants in the form of a “white cloud” which rises rapidly from the galvanizing bath as a result of the thermal currents.

The purpose of this study is to improve the corrosion resistance of the transmission towers by Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) in Q345 steel.

The phase structure of Zn-Al-Mg-Re composite coatings has been determined by X-ray diffraction, whereas their surface morphology and cross-sectional microstructure as well as cross-sectional elemental composition have been analyzed by scanning electron microscopy and energy-dispersive spectrometry. Moreover, the corrosion resistance of Zn-Al-Mg-Re composite coatings has been evaluated by acetic acid accelerated salt spray test of copper strip.

Experimental results show that doping with La and Ce favors to tune the composition (along with the generation of new phase, such as LaAl₃ or Al₁₁Ce₃) and refine the microstructure of Zn-Al-Mg galvanizing coatings, thereby significantly improving the corrosion resistance of the coatings. Particularly, Zn-Al-Mg-Re with 0.15% (mass fraction) La exhibits the best corrosion resistance among the tested galvanizing coatings.

Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) have been prepared on Q345 steel substrate by hot-dip galvanizing so as to improve the corrosion resistance of the transmission towers, and to understand the corrosion inhibition of the Zn-Al-Mg-Re coating.

In 1742, the French chemist Melouin presented a paper to the French Royal Academy in which he described how a zinc coating could be applied to iron by dipping it into molten zinc. The first patents covering the ‘galvanizing’ process were taken out in France and England during the 1830's; the name being taken from that of the Italian physiologist Luigi Galvani who observed that electric current could be generated when dissimilar metals are brought into contact.

Introduction Over the last fifteen years the tonnage of zinc used by the U.K. general galvanizing industry has increased by about 15%. During the same period the tonnage of steelwork galvanized has increased by over 50%. These figures indicate a change in the pattern of use of galvanized steel and, in this article, these changes and the reasons for them will be discussed. The galvanizing industry is embarking on an expanded marketing campaign and there is every indication that, under the impetus of this campaign, the tonnage of steel galvanized will be still further greatly increased.

The ability of zinc to inhibit the rusting of steel depends on a natural phenomenon — the electrical reaction between dissimilar metals, first noted by an Italian scientist named Luigi Galvani. A French chemist discovered in 1740 that zinc could protect steel from the effects of rust. However, it would be almost 100 years before the practical problems of coating steel with zinc would be solved. In 1887 Stanislaus Sorel, a French engineer, secured a patent for hot dip galvanizing. It is basically on this method that today's techniques have been developed. Recognizing Galvani's earlier discovery, Sorel called his process Galvanization.

Substantial savings in protection costs can be achieved with greater use of hot dip galvanizing. Brian Lansley, marketing manager at the Galvanizers Association discusses the economic benefits offered by galvanizing over other corrosion protection systems.

The hot‐dip galvanizing process had its inception in the work carried out by a French chemist, P. J. Melouin, about the year 1742. The industrial application of a zinc coating to iron and steel articles by hot dipping dates back to the late 1830s, and galvanizing works are known to have existed in London and the Midlands at about that time. Though the industry is therefore one which has been established for a long time, it is by no means old‐fashioned in its outlook.

The purpose of this work was to investigate the effect of Si content of steel substrate on the performance of the hot-dip galvanized layer. Moreover, the structure of the galvanized layers and the corrosion performance of the galvanized steel in 3.5 per cent NaCl solution have been studied.

The galvanized layer has been formed by the hot-dip technique, and the influence of silicon content in the steel composition on the corrosion performance of the galvanized steel was estimated. The surface morphologies and chemical compositions of the coated layers were assessed using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. Potentiodynamic polarization Tafel lines and electrochemical impedance spectroscopy (EIS) tests were used to evaluate the corrosion resistance of the galvanized steel in 3.5 per cent NaCl solution.

The results proved that adhere, compact and continuous coatings were formed with steel containing 0.56 Wt.% Si, while cracks and overly thick coatings were obtained with steel containing 1.46 Wt.% Si. Tafel plots illustrated that the corrosion rate of galvanized steel containing 0.08 and 0.56 Wt.% Si was lower than that of the galvanized steel containing 1.46 Wt.% Si. Also, the results of the EIS reveal that the impedance of the galvanized steel containing 0.08 and 0.56 Wt.% Si was the highest and the lowest, respectively, with the steel containing 1.46 Wt.% Si.

Generally, in industry steels containing high amounts of silicon (0.15-0.25 Wt.%) can be galvanized satisfactory either by controlling the temperature (440°C) or adding Ni to the galvanized bath. The low temperature reduces the coating thickness; nickel amount must be controlled to prevent the formation of higher amounts of dross. This study proved that high Si steel of up to 0.56 Wt.% can be galvanized at 460°C without adding Ni to the galvanized bath and form adhere, compact, free cracks and have good corrosion resistance. Consequently, a social benefit can be associated with galvanizing high Si steel, leading to an increase in the cost of the process.

The results presented in this work are an insight into understanding the hot-dip galvanizing of high Si steel. The corrosion resistance of galvanized steel containing 0.56 Wt.% Si alloys has been considered as a promising behavior. In this work, a consistent assessment of the results was achieved on the laboratory scale.