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How to Identify Substandard Steel

How do you identify substandard steel?

  1. Tensile strength test
  2. Rebend test
  3. Metallurgical test
  4. Hardenability test

 

One of the most widely-used construction materials is steel. Many industries have preferred it over other types of material because of its highly-attractive properties, bringing stability to various structures. Apart from being flexible and durable, it is also highly versatile, allowing construction industries to use the material in a variety of ways for many different purposes. However, not all steel is manufactured in the same way. If you can’t tell what substandard steel is, then the simple guide below will provide you with information on the parameters you should look out for when identifying constructional steel quality.

 

Tensile strength test

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The tensile strength test is just one of the most common ways by which the mechanical properties of a particular metal is determined. Simply put, a tensile strength test determines the capacity or load which a material can withstand, through stretching, before it is subject to breakage or fracture. Several other properties are also determined with the conduction of a tensile strength test, like yield strength, or breaking strength.

Through a yield strength test, there is an application of a particular level of stress on the material. The point at which the material receives permanent deformation is what ultimately determines this property.

If this test were applied to steel, one needs only to divide the cross-section of the steel, by the quantifiable level of stress placed on it.

It would therefore not be judicious for construction industries to make use of steel with low tensile strength. This would lead to instability in a structure’s foundation which might cause further unwanted building outcomes.

 

Rebend test

Another quality that makes steel one of the most widely-utilized construction materials is its flexibility. This property of steel has enabled many industries to get creative in the way to incorporate steel into their products and other services.

One particularly useful application of steel in construction processes is the rebar, which is also known as reinforcing steel. This construction material is most commonly used to provide structure and shape to concrete. To increase its bond with the concrete, repeating patterns are etched onto the material.

Since this material provides support for concrete pillars or building foundations, for example, it’s important that the rebar passes the rebend test. This test involves bending the bar at an angle of around 135 degrees. After this, the bar is submerged into boiling water for around half an hour.

If the bar shows some cracks or breakage after it is pulled out of the water, then it would be judicious to do away with the steel and find another higher-quality version. The rebar is, after all, the material that holds the concrete structure together. It would be dangerous for construction industries to make use of shoddy material in their operations.

 

Metallurgical test

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While the first two testing methods employ a more chemical approach, there is another way of determining steel quality through the metallurgical test. Through this test, the steel sample is microscopically analyzed.

Since steel can be alloyed with different kinds of metals to improve or alter its properties, the metallurgical test is a good way of determining which properties of the steel sample has changed. These parameters can include grain size, shape, and inclusions of nonmetallic material.

Employing this kind of test will help predict the kind of behavior the steel will exhibit under certain conditions.

It is generally easy to determine the quality of the steel through the metallurgical test. If a steel sample is tested under a microscope and it has been found that the size of the grains is much smaller, then the steel is generally tougher compared to a sample that has much larger grains. There are different reasons which can contribute to the quality of the grain, through several steel-strengthening methods such as heat treatment which can largely affect the composition of the grain.

While steel with coarser grain composition is not necessarily considered as sub-par steel, the preferred material would definitely be that of a tougher one, especially if the aim of the construction company is to provide durability in their structures.

 

Hardenability test

Also known as the Rockwell Test, this test determines a metal’s ability to resist several levels of indentation. This test involves gauging the depth of the dent, which determines how tough the material is.

Since this test can be applied to different kinds of metals, applying this test on steel would also not be relatively difficult to achieve. The step first begins with the application of a load on the material. After this, the depth of the dent is measured.

Since steel is a highly durable material, employing this test on different samples of steel in different gradings would be beneficial in determining how tough the steel variation is. A steel sample that has tested low on this property should not be considered for use by construction companies who are looking to utilize only the best kinds of materials.

 

Key Takeaway

There are many different mechanical and chemical-based testing methods to determine what substandard steel is. While the usage of a lower-grade version of steel is generally not accepted especially in constructional endeavors, this mistake will inevitably be made if you’re not equipped with the right information. With Regan Steel, however, you can always be assured that our construction materials are of the highest-grade, and have satisfactorily passed all kinds of durability testing. Always make sure to consult with us if you want to avail of higher-quality constructional needs.