Coal is a key part of the coke-making process. As the oven is heated, the coal begins to melt so most of the volatile matter such as oil, tar, hydrogen, nitrogen and sulfur are removed. The cooked coal, called coke, is removed from the oven after 18 to 24 hours of reaction time.
The coke is cooled and screened into pieces ranging from one inch to four inches. The coke is a porous, hard black rock of concentrated carbon contains 90 to 93 percent carbon , which has some ash and sulfur but compared to raw coal is very strong. The strong pieces of coke with a high energy value provide permeability, heat and gases which are required to reduce and melt the iron ore, pellets and sinter.
Alternatively with the EAF method, recycled steel is fed into an electrical ark furnace along with the molten iron which is then heated to around degrees Celsius in order to convert it into high-grade steel. Next the newly formed molten steel needs to be adjusted to make the perfect steel composition. This may include processes such as degassing, stirring, ladle injection, or argon bubbling. Now we have the bones of our steel the next step is to pour it into cooled moulds.
This causes the the metal to cool quickly. Once cooled the metal is then cut into desired lengths depending upon the application eg, slabs for plates, blooms for sections such as beams, and billets for longer products such as wiring or thin pipes. Also known as primary forming, the initial shapes of slabs, blooms, and billets are formed into their various shapes usually by hot rolling.
Products that are hot rolled are then divided into flat products, long products, seamless tubes, and speciality products for one last stage of processing. Finally a variety of secondary forming techniques including shaping, machining, jointing and coating give the products their tell-tale shapes and properties. So there you have it, the entire steel making process in 6 steps! We have the skills and the experience to construct just about anything you want.
To get the impurities out, the molten metal is infused with scrap steel. Oxygen will be forced through the furnace as well, which gets out a lot of the carbon and other impurities. For electric furnaces, electricity will be forced through the furnace and the same results can be achieved.
After this process has finished, we have raw steel. The different grades of steel are used for different tasks. The grading is based on which elements are still in the metal, such as carbon dioxide. A lot of the carbon will be removed, but aluminium will take its place to create a Drawing Quality steel. To create structural steel, there is more carbon left inside, and this gives the steel more tensile strength.
Certain techniques can be implemented to alter the level of impurities left, including:. Next, the steel in its molten form is cast into cooling moulds.
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