what is the refining process doing to raw materials in steel
As Mr. Perfessor says, refining raw steel involves a lot of purifications of the raw steel; and to expand a bit, these refining processes also add corrosion-resistances to certain graded steels, and durability factors, when heat-tempering processes are used. All of these refining processes, and coating processes help steel products last when exposed to moistures, salts, and other corrosive conditions that steel can be exposed to, whether the steel is in open-air/water/space, embedded in concretes and other masonry products, or part of a protective barrier system in power plants, engines, etc. Hope this also helps; the eggster.
The refining process removes impurities. Impurities are anything that is not iron (Fe). Most steels are at least 98% iron, with a fraction of a percent of carbon, a dash of manganese, and traces of sulphur and phosphorus. These are called carbon steels. The non-iron elements are impurities found with the iron in the ore. A certain amount of carbon and manganese is beneficial to the strength of steel, so part of the refining process is designed to control the carbon and manganese content to give desired properties to the steel. Sometimes small amounts of these are added in the process. Besides the common carbon steels, there are many alloys of steel in use today. Alloying is done after the steel is refined to over 98% iron, and while it is a liquid. Various elements are added to the steel in controlled amounts to give it special properties. These include silicon, aluminum, magnesium, vanadium, beryllium, nickel and chromium, and sometimes molybdenum, tungsten and titanium. Alloy steels are still mostly iron, ususally at least 95%, but some stainless steels are only 75% iron because of large amounts chromium and nickel added to the mix.
Refining process for steel include burning out the extra carbon and impurities with oxygen lancing and protecting the steel from atmospheric gas inclusion by protective environment during such process . Measured % of ferralloys are also added to produce various grades of steel . These may be done in induction furnace/ laddle refining furnace / crucibles converters etc.
