Steel is possibly the most important engineering and construction material in the world, thanks to its material properties. It’s hailed as the strongest and one of the most customizable alloys because, depending on the added elements, steel’s properties will be more enhanced. It’s no wonder things made of said alloy, like steel plates, are essential in the Philippines and around the world.
The most important properties of steel are its great formability and durability, good tensile and yield strength and thermal conductivity. Another chief characteristic of steel is its high resistance to corrosion.
When choosing a material for a specific application, engineers must be able to select the one suitable for the loading conditions and environmental challenges the metal will be subjected to while in service, making understanding and controlling a material’s properties necessary. The mechanical properties of steel can be controlled through the selection of an appropriate chemical composition, processing and heat treatment. This will lead to the final microstructure of steel.
The alloys and the heat treatment during production will result to different property values and strengths. Testing must be done to determine the final properties of a piece of steel to make sure it passed certain standards.
The properties that need to be considered when specifying steel construction products are:
Tensile testing is a method of evaluating the structural response of steel to applied loads, with the results expressed as a relationship between stress and strain. There are four different types of ways to measure the strength of steel, and all metals for the matter: yield, compressive, impact, and tensile.
Toughness may be measured by impact testing. Although it is in the nature of all materials to contain certain imperfections, steel’s imperfections must only come in the form of very small cracks. If the steel is insufficiently tough, these cracks can propagate rapidly and result in a brittle fracture. The risk of brittle fracture increases with thickness, tensile stress and colder temperatures.
Ductility is a measure of the degree to which a material can elongate between the onset of yield and eventual fracture under tensile loading. Engineers rely on ductility for a number of aspects including reduced risk of fatigue, crack propagation, bending and straightening.
All structural steels are weldable. However, welding involves melting the steel, which eventually cools. The cooling can be quite fast because the surrounding material, for example the beam, offers a large heat sink and the weld is usually relatively small. This can lead to hardening of the heat affected zone and the toughness to be reduced.
Another important property of steel is corrosion resistant. There are special corrosion resistant steels that are available although these are not normally use for building construction. The most common means of providing protection against corrosion is by painting or galvanizing. The type and degree of coating protection required depends on the degree of exposure, location and design life, among many others.
Steel definitely proved itself as a very useful part of the society. Without it, we wouldn’t be able to experience modernization as we know it.