How Black Carbon Steel is used

Posted on Feb 2 2018 - 2:27pm by Johnny B

Many folk reading this will already be aware that steel is made from a mixture of iron with carbon and smaller amounts of other metal types. Pure iron can be melted down and then shaped, but because it is somewhat soft, it needs the addition of carbon, to help it to harden.

Black carbon steel is generated during the course of the manufacturing process when the high temperature creates a thin layer of oxidized iron on the outer surface.

  • Nearly all carbon steels are made up of one to two percent carbon.

Carbon chemically unites together with iron in steel alloys, which then goes on to create a much stronger material than just pure iron. After the carbon content has been increased, the material then becomes more solid, but also slightly brittle, and more than likely to break if it is placed under any kind of stress or load.

Steel which contains above 2% carbon is considered as cast iron that can be put to use for things such as piping and non-building materials, although it is deemed too brittle for structural steel.

Rust and Corrosion Resistant

Iron reacts with oxygen when exposed to air or moisture, and will then begin to generate iron oxide (AKA “rust”), which then causes parts to fail, so it is typically coated by lacquer colouring specialists, so as to prevent any surface rust.

  • One ideal benefit of black carbon steel is its anti-corrosion property from the black iron oxide coating,. This blocks oxygen from getting to the iron underneath.

The thin oxide coating is made at high temperatures, which then creates a firm layer with no more coating required. There is also one more method used for cold chemical, metal blackening of steel, (and other ferrous metals), which is made possible through the process of working at room temperature without any need for a hot solution.

  • To apply exactly where corrosion protection is required, carbon steel must be either painted or galvanised.

Galvanising is conducted via an acid wash and then being immersed into a molten zinc bath. The zinc, then creates a protective layer on the steel. Galvanizing also helps to extend the working lifespan of all steel parts.

Where it is used

Mostly, black carbon steel is used on gas or water utility piping, because of its low cost and ability to be welded by common welding methods. Some long-distance oil pipelines use black carbon steel piping, due to the pipes being easy to connect out in the field, and their rust resistance.

This type of steel can be used in various climates and conditions where corrosion would normally accelerate, although there may have to be some additional treatment applied by way of anodes.

Black Steel Cookware?

Have you ever seen any cookware called black steel? Well, that dark colouring is actually the product of a special oil treatment known as “seasoning”, and not from manufacturing.

Black carbon steel will definitely be in use for us for a very long time!