Steel Fabrication: Materials Used for Hot Dip Galvanizing

Malleable iron, cold rolled steels, hot rolled steels, and cast iron can all be protected by a process called hot dip galvanizing. Structural metal shapes, such as those of strong low allow materials, undergo this process after fabrication, to achieve a long-lasting protection provided by the zinc coating.

Steel compositions differ depending on the service and strength requirements. The primary elements in steel, like carbon silicon, can impact the necessary galvanizing techniques and the appearance and structure of the zinc coating. For instance, when certain elements are present in the steel, the coating could be nearly all or all zinc-iron alloy.

Here are the characteristics of a nearly all or all zinc-iron alloy coating:

Appearance

The visual appearance of zinc-iron alloy coating may have a hazy grey look because there's no free zinc layer. It is this layer that gives the bright finish to a galvanized coat.

Adherence

The galvanized coating which is nearly all or all zinc-iron alloy have a lower adherence than the typical galvanized coat. Such kind of coating is likely to be thicker compared to the typical galvanized finish. As this type of coating thickens, the adherence may be reduced.

Corrosion Resistance

Generally speaking, a galvanized coating is specified more for its ability to resist corrosion than for its visual appearance. So, a designer's main interest is the corrosion resistance of the two types of coatings. Consumers and fabricators must know that while a matte or grey appearance may happen, such appearance doesn't reduce the steel's long-range atmospheric protection. For practical purposes, the coatings' ability to resist corrosion is equal.

It's not very easy to provide accurate guidance to a designer in terms of steel usage, without qualifying the grades of steel available in the market today. But the following guidelines will help you choose steel possessing ideal galvanizing characteristics:

Plain carbon structural-grave steel will, most of the time galvanize with the manufacture of a typical steel coating. But, many believe that manganese level less than 1.35 per cent, phosphorous level less than 0.05 per cent, or carbon level less than 0.25 per cent are beneficial. On the other hand, silicon at levels lower than 0.04 per cent or between the range of 0.15 per cent0.25 per cent is ideal.

Silicon is present in many types of steels which are commonly galvanized, though it isn't a part of the controlled composition of steels. This happens mainly because silicon is used in the process of de-oxidation of the steel, and is usually found in cast steels.

Steels with higher levels of silicon may display bright and shiny areas next to grey matter areas. This is due to the distribution of silicon. An effective method for combating the impacts of steel with high silicon content is to add a certain amount of nickel, often between 0.05 per cent and 0.09 per cent to the zinc bath.

The steel galvanizer must always be aware of the grade of a certain steel, so he or she can determine whether or not other galvanizing techniques are necessary.


----------------------------------------------------
If you are looking for galvanized steel and other fabricated steel products online, visit tcg industries to check out their line up of high quality, durable, and affordable galvanized steel products. Simply follow these links for more information: http://tcgindustries.jigsy.com/entries/business/understanding-the-complicated-steel-fabrication-process http://tcgindustries.wordpress.com/wind-the-drum/