Those out there reading this will probably know that steel is a combination of iron with carbon and smaller measures other metals. Pure iron indeed can be melted and then shaped, but it also happens to be slightly soft, and with the addition of carbon, it helps to harden the metal.
Black carbon steel is made in the course of the manufacturing procedure when the high temperature forms a thin layer of oxidized iron on the exterior surface.
- Most carbon steels consist of one to two percent carbon.
Carbon chemically unites with the iron in steel alloys, which generates a much more durable material than just pure iron. After the carbon content has been increased, the material becomes more solid, but it also becomes somewhat brittle, and likely to break should it be under any type of stress or load. Steel which contains over 2% carbon is considered cast iron that can be utilised for the likes of piping and non-building materials, but is deemed too brittle for structural steel.
Rust and Corrosion Protection
Iron reacts with oxygen when in the air or moisture, and will then create iron oxide (or rust), which causes parts to fail, so it is commonly coated by lacquer colouring experts to prohibit any surface rust.
- One great advantage of black carbon steel is its anti-corrosion property from the black iron oxide coating, due to oxide blocking oxygen from the iron underneath.
This thin oxide coating is made at high temperatures, which develop a firm layer with no further coating required. There is also another technique used for cold chemical, metal blackening of steel, (and other ferrous metals), which is made possible via the process of working at room temperature without the requirement of a hot solution.
- To administer where corrosion protection is crucial, carbon steel has to be painted or galvanized.
Galvanizing is carried out through an acid wash and then the dipping of the steel into a molten zinc bath. The zinc, then forms a protective layer on the steel. Galvanizing also helps to improve the working lifespan of all steel parts.
Where you will see it Being Put to Use
In most cases, black carbon steel is put to use on gas or water utility piping, due to its low cost and its ability to be welded with typical welding techniques. Some long-distance oil pipelines make use of black carbon steel piping, because of the pipes being easy to connect out in the field and their resistance to rust. It can be used in different climates and conditions where corrosion normally accelerates, but there may have to be some extra treatment applied by way of anodes.
In the Kitchen
You may have seen some cookware being called “black steel”, but actually that dark colouring is a product of a special oil treatment known as “seasoning”, not from manufacturing.
Black carbon steel will be with us for a very long time!