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Tianjin Haigang Steel Coil

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2020-05

Galvanized strip steel products boast excellent characteristics such as strong corrosion resistance, superior surface quality, suitability for advanced processing, and cost-effectiveness. As a result, they are widely used in various fields including architectural decoration, rolling shutter doors, colored doors and windows, residential chimneys, agriculture and sideline industries, aquaculture, household appliances, cable belts, and more. Typically, they are employed to manufacture steel pipes—for example, greenhouse pipes, water supply pipes, heating pipes, and gas transmission pipes—and can also be applied in industries such as construction, light industry, automotive, agriculture, animal husbandry, fishery, and commerce. In the construction sector, they are primarily used to produce corrosion-resistant roofing panels and roof grids for industrial and civil buildings. In the light industry, they are utilized to fabricate appliance casings, residential chimneys, kitchenware, and other items. In the automotive industry, they are mainly employed to manufacture corrosion-resistant components for passenger cars. In agriculture, animal husbandry, and fishery, they serve as equipment for grain storage and transportation, as well as for the frozen processing of meat and aquatic products. In commercial applications, they are commonly used as storage and packaging tools for goods, as well as for structural steel purlins (C- and Z-shaped steel), lightweight studs, and ceiling joists.

2020-05-22

2020-05

The difference between electro-galvanizing and hot-dip galvanizing

Steel is highly susceptible to corrosion when exposed to air, water, or soil. The annual losses caused by corrosion account for roughly one-tenth of total steel production. To impart specific functional properties to metal surfaces and give them an aesthetically pleasing appearance, electro-galvanizing is commonly employed. Since zinc does not readily change in either dry or humid air, a highly dense film of zinc oxide can form on its surface, effectively protecting the underlying metal from corrosion. Moreover, if the coating is damaged for any reason, exposing the base metal, the zinc and steel substrate will form micro-pores, turning the base metal into a cathode and providing it with additional protection. This process is widely used in industries such as automotive and transportation; however, to reduce the harmful and toxic effects of hexavalent chromium passivation, trivalent chromium conversion coatings and zinc-nickel alloy plating are often applied. Electroplated zinc coatings are thick, have fine and uniform crystal structures, are free of pores, and exhibit excellent corrosion resistance. The zinc layer obtained through electroplating is relatively pure, corroding slowly even in acidic or alkaline fumes, thus providing effective protection for the metal substrate. After chromate passivation, the galvanized layer develops colors ranging from white and colorful hues to military green. These coatings are both elegant and visually appealing, offering significant decorative value. Due to the excellent ductility of the zinc layer, it can be shaped through cold stamping, rolling, bending, and other processes without damaging the coating itself. Electroplated zinc is increasingly being adopted in a growing number of fields. Fastener products are now extensively used in sectors of great importance to the national economy, including mechanical engineering, electronics, precision instruments, chemical industry, transportation, aerospace, and others. Among the various hot-dip galvanizing methods used for surface protection of substrates, hot-dip galvanizing stands out as an exceptionally effective technique. In hot-dip galvanizing, the zinc used is in liquid form; after undergoing complex physical and chemical reactions, this method not only deposits a thicker zinc coating onto steel fasteners but also forms a zinc-iron alloy layer. This galvanizing method not only retains the corrosion-resistant characteristics of electroplated zinc but, thanks to its zinc-iron alloy layer, offers superior corrosion resistance that cannot be matched by electroplating alone. Consequently, this galvanizing method is particularly well-suited for use in environments characterized by severe corrosion, such as those exposed to strong acids and strong alkalis. This type of metal is widely utilized in the construction of power transmission towers. In principle, the hot-dip zinc coating is formed in three distinct steps: First, the iron-based surface is dissolved by the molten zinc, creating a zinc-iron intermetallic layer. Next, zinc ions from the alloy layer further diffuse into the substrate, forming a zinc-iron solid-solution layer. Finally, the surface of the alloy layer is covered by a protective zinc layer.

2020-05-21

The difference between electro-galvanizing and hot-dip galvanizing

2020-05

The production process of galvanized strip steel

2020-05-18

2020-05

Can galvanized strip steel be stored outdoors?

Galvanized strip steel is a process in which a layer of zinc is applied to the surface of strip steel through high-temperature and chemical treatments. Compared to ordinary steel, galvanized strip steel boasts numerous advantages, such as superior corrosion resistance, longer service life, and enhanced rust resistance. As demand continues to grow, so does the demand for galvanized strip steel. Given these many benefits of galvanized strip steel, factories should pay close attention to effective storage methods during manufacturing. After all, even durable materials can be damaged—galvanized strip steel is no exception. Although it has a bright and attractive appearance, it cannot withstand prolonged exposure to sunlight. Metal materials require a dry storage environment; however, it’s crucial not to expose them to direct sunlight for extended periods. Prolonged exposure to the sun can cause the zinc coating on the surface of galvanized strip steel to flake off, thereby shortening its lifespan. If left outdoors for long periods, galvanized strip steel will not only suffer from intense sunlight but may also be exposed to heavy rain and lightning strikes. Such prolonged exposure to wind and rain can severely corrode the steel, making it highly detrimental to its condition. Tianjin Haigang Steel Coil Co., Ltd.—we have professional bundling personnel and scientifically designed packaging methods, doing everything possible to extend the storage life of strip steel.

2020-05-12

Can galvanized strip steel be stored outdoors?

2020-05

Do you know what the effect of passivation is?

Passivation refers to the corrosion products formed on a metal surface due to the action of certain media. If these products have a dense structure, they can form a thin film—often so thin that it is invisible—that tightly covers the metal’s surface, thereby altering the metal’s surface state and causing its electrode potential to shift dramatically toward the positive direction, transforming the metal into a passivated, corrosion-resistant state. For example, when Fe is oxidized to Fe²⁺, its standard electrode potential is –0.44 V; after passivation, this potential jumps to +0.5 to 1 V, thus exhibiting enhanced corrosion resistance. This thin film is called the passivation film. Metal passivation can also occur spontaneously over time (such as the formation of aluminum oxide). In industrial applications, passivators—primarily oxidizing agents—are typically used to treat metals, forming a dense passivation film that slows down the rate of metal corrosion.

2020-05-11

Do you know what the effect of passivation is?

2020-03

Do you know how galvanized strip steel is de-rusted?

Acid pickling for rust removal is a critically important step in the hot-dip galvanizing process. Whether or not a high-quality surface finish can be achieved on the workpiece prior to plating—and how we can improve quality and reduce consumption during the hot-dip galvanizing process—both hinge on the pivotal role played by this acid pickling stage! At the same time, the environmental pollution and ecological pressures generated by this process have become a major source of concern and headache for our hot-dip galvanizing enterprises! In recent years, China's galvanizing industry has been expanding rapidly, and with it, issues such as environmental pollution, wastewater treatment, and emissions have become increasingly prominent.

2020-03-05

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We primarily produce various products including galvanized strip steel, pickled strip steel, and cold-rolled strip steel. These products are widely used in industries such as construction, mechanical manufacturing, automotive, and household appliances.

Contact Information

Company address:

Shuangtang High-end Hardware Products Industrial Park, Jinghai District, Tianjin City

Contact phone number:

(86-22) 68778999/ 68508999

Corporate email:
tjhaigang@tjhaigang.com

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