Mild steel (also known as low carbon steel) has received abundant coverage on the Austen Knapman blog, yet we’ve barely begun to crack the surface on what this exceptionally versatile, widely available metal can do! From steel frame buildings and machinery to cookware, pipelines and trainlines, you’re likely to come across mild steel every day is some radically different shape, with the following being just five of the material’s unique properties worth noting.
With the addition of less than 2% carbon, mild steel is stronger and stiffer than many other types of metal, whilst also giving it enhanced uses within a multitude of processes such as cold forming and heat treatment. Whilst its load strength isn’t usually enough on its own to use it in structural beams and girders, the affixing of carbon atoms into the interstitial sites of the iron matrix prevent dislocations from happening within the iron crystals, stopping the lattice layers from sliding past each other – making mild steel even harder than iron.
#2 Less Brittle
The minimal use of carbon in mild steel ensures not only a high density (usually 7.85 gm/cm 3), but a greater level of flexibility too. As a softer metal, mild steel can be easily melded, which sets it apart from higher carbon steel (such as stainless steel) which need specific welding tasks to suit an individual construction project, which in mild steel’s case includes sheet metal, bars, rods and sections. Machined and shaped easily thanks to its inherent flexibility, mild steel can be further hardened through carburizing, making it a top choice for an endless selection of consumer products.
A top choice when constructing electrical devices and motor parts, mild steel’s particular makeup (no more than 25% carbon) means it can be magnetized by a relatively small field, which when removed reverts it to a low residual magnetism. Ferromagnetic materials like mild steel are not only strongly attracted to magnets, but they can also themselves be formed into permanent magnets for a variety of manufacturing uses. Mild steel’s magnetism also makes it one of the easiest commercial metals to recycle, since it can be easily sorted from mixed waste.
The specific make up of mild steel allows electricity to flow through it with ease, without impacting its structural integrity. Conversely, whilst stainless steel is usually made up with about 25% chromium for added corrosion resistance (something which can cause mild steel to rust easily without surface finishing/treatments), the atoms of this chromium disrupt the crystal lattice that would normally allow electrons to be easily shared i.e. making it a poor conductor.
Last but not least, mild steel is also notoriously the cheapest of commercially available steel to produce. Though steel in general requires a lot of energy to make, mild steel requires the least of them all. This ease of manufacturing makes it the main metal of choice for bridges, buildings, ships and vehicles, as it helps keep overall energy outputs and costs down to a minimum.