Galvanized Steel Sheet Corrosion

               Depending on the applications, steel sheet will need to have an extra layer of protection to help defend corrosion that naturally occurs over time. In order for manufactures and distributors of steel products to ensure the material they are using in their projects will last, the steel is often galvanized. Galvanization is done via a hot dipping method, coating the product in a layer of Zinc.  While the protective coating is designed to further safe-guard the steel sheet’s future, corrosion is a process that is hard to fully avoid. galvanized steel sheet is still susceptible to corroding – whether that be because of natural, chemical or electrochemical conditions.

                The degree and speed of a steel product’s corrosion depends on a few factors – though in the majority of cases will gradually occur overtime.  The type of steel, the thickness of protective Zinc on the steel sheet, and the product’s environment all play major roles in steel sheet corrosion.

Natural Corrosion

              Galvanized steel sheet that has is exposed to the atmosphere and rainwater is likely to corrode overtime. The product develops a natural carbonate on it that becomes brittle and will eventually crack and split. The split exposes a new layer of zinc that will corrode, and it can even corrode enough to expose the base layer of steel to the atmosphere and its elements. 

Chemical Corrosion

               Steel sheet that has been galvanized has the ability to resist corrosion from a number of chemicals it comes into contact with including concrete, lead, tin and aluminum. However there are some chemicals that will reduce the products’ protection to corrosion: plaster and cement with chlorides and sulfates, acidic rainwater runoff, zinc plate condensation, moss, lichen, and pooled water on the exterior of the zinc coating.

Electrochemical Corrosion

              Certain electrolytes that come into contact with the zinc layer on galvanized steel sheet can cause an electrolytic reaction.  Some electrolytes that could have an effect include rain, fog, condensation and dew. In order to avoid the reaction, prevent contact between the galvanized steel sheet and electrolytes as much as possible. Another solution is applying paint to the galvanized product to thwart corrosion of the coating of zinc.

Steel Tube and its Applications

                 Steel tube, a term that is often interchanged with steel pipe, has been used throughout the past thousands of years for a wide array of applications. This versatile product is one of the most often manufactured and distrusted steel products by companies in the steel industry. Steel pipe is made to be strong and durable, yet it is lightweight and customizable to different applications making it the perfect product throughout several industries. 

                 Depending on the intended purpose, Steel Tubes can be manufactured in various lengths and thicknesses. It also can be made in to different shapes other than round, which include rectangular, triangular or square. The flexibility and functionality of steel pipe can be found in several different places. One of the most common applications is using the product to transport both water and gas throughout neighborhoods, towns, and cities using an underground system. The strength of steel tubes makes it possible for it to withstand the conditions of being buried.

                 Another common application is its use in the construction industry for a number of different things. Steel tubes are used to create the foundation of buildings, balconies or staircase railings, and to protect various electrical wires. Steel tube piles are also often used during construction – a method to strengthen a foundation that is unstable or may be supporting a heavy load.Some other places steel tubes can be found are in bicycle frames, refrigeration units, all types of automobiles, furniture parts and in systems used for both heating and plumbing. It is such a popular product when it comes to the transportation of water because the product does not contaminate the water, and because of its ability to handle intense pressure. 

                 Millions of tons of steel pipe are produced each year to reach the wide demand for steel tube products. While steel tube is made through several different processes, the overall manufacturing process for each steel pipe production method include three similar steps. The raw steel, which is primarily made of iron, must first be made into a more workable form – molten steel. Then, it is poured into molds that form the pipe before it is cut to a specified length to fit customers’ need.Steel pipes also go through testing after they are created to make sure the meet the manufacturer’s standards.Other methods and measures may be implemented after to meet the client’s specified requirements.

                 Due to steel tube’s resistance to corrosive elements and its ability to withstand high heat and high pressure, it remains to be a popular choice for countless purposes and one of the highest in-demand products for companies that manufacture steel products. Its versatility extends from its common functions in the home and the transportation and construction industry, to not as known uses including earth retaining walls and bridges.  The ability to customize steel pipes and the control that it gives people using the product is a highly-appreciated and attractive feature.

Are Steel Tubes Contributing to Tainted Water in Shale-Gas Areas?

Recent studies have emerged placing blame on steel tubes and bad cement for tainted drinking water in shale-gas areas.  Hydraulic fracturing was previously suggested to be the cause for water contamination in areas where natural gas is produced.  A new analysis published in The Proceedings of the National Academy of Sciences has confirmed what many have believed as of late.  The analysis proclaims, “there is no evidence that fractured shale led to water contamination” near several natural gas drill sites in Pennsylvania and Texas.   Fault lies with, for the time being, improperly built wells which lead to gas leaking up the wells into aquifers.

            The first step in the extraction of natural gas is carried out by gas producers who drill a deep vertical well which extends horizontally in several different directions.  Picture these expansion shafts as spokes protruding from a center hub.  A combination of steel pipe and cement are then used to line and seal the outside of the vertical wells.  What happens next is referred to as hydraulic fracturing or fracking.  Fracking involves injecting water and chemicals at high pressures into the “spokes”, creating fissures and releasing the natural gas trapped within the shale.  Why hydraulic fracturing was initially thought to cause gas to migrate into drinking water aquifers is a plausible explanation.  However, researchers concluded that fissures created by fracking are not long enough to affect aquifers. 

Thus, attention was focused on the next possible cause, gas leaking out of the steel lined and cement sealed vertical well.  Unfortunately, well integrity is a widespread problem in the oil and gas industry.  Scott Anderson, who deals with energy production issues for the Environmental Defense Fund, revealed that “15% of all cement sealing of wells may be imperfect”.  Mr. Anderson believes that improvements in well integrity could eliminate environmental problems caused by gas leaks.  He even offers suggestions that gas producers could us in taking steps towards eliminating leaks.  For example, ensure the proper cement and steel tubing is used as well as monitor pressures during well construction and while gas is flowing. 

Could imperfect wells be related to smaller companies with a lack of drilling experience in some shale-gas areas?  There are statistics that show a correlation between larger companies drilling better wells.  Although, according to Scott Anderson, this may not necessarily be true.  “Some of the best wells, from a technical standpoint, are drilled by the smallest operations.”

Now that the cause of the issue at hand has been determined, will the government implement changes to the process of natural gas production?  What steps will gas companies implement in order to prevent leaks from occurring in the future?  Hopefully imperfect wells are not the result of pure negligence by gas companies and there really are improvements that can be made towards improving well integrity.