R

Reducing Agent
Either natural gas or coal can be used to remove the oxygen from iron ore in order to produce a scrap substitute. In gas-based processes, the iron ore is heated in a vessel as reformed natural gas passes through. In coal-based processes, iron ore is combined with gasified or ground coal and heated. The oxygen in the ore combines with carbon and hydrogen in the gas or coal, producing reduced, or metallic, iron.

Refractory Brick
Heat-resistant brick. Because its melting point is well above the operating temperatures of the process, refractory bricks line most steelmaking vessels that come in contact with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF.

Reinforcing Bar (Rebar)
A commodity-grade steel used to strengthen concrete in highway and building construction.

Reline
The process of replacing the refractory lining of a liquid steel vessel. Once it wears out, the brick lining of a furnace must be cooled, stripped and replaced. This maintenance can be significant because a blast furnace reline may require up to three months to complete.

Residuals
The impurities in mini-mill steel as the result of the mix of metals entering the process dissolved in obsolete scrap. Residuals are key concerns regarding the mini-mills' recent entry into the flat-rolled market, where high residuals can leave sheet steel too brittle for customer use.

Reversing Mill
The stand of rolls used to reduce steel sheet or plate by passing the steel back and forth between the rolls; the gap between the rolls is reduced after each pass.

Rod
Round, thin semi-finished steel length that is rolled from a billet and coiled for further processing. Rod is commonly drawn into wire products or used to make bolts and nails. Rod trains (rolling facilities) can run as fast as 20,000 feet per minute

Roll Force Systems
Mill stands place considerable pressure on slabs, blooms and coils to further process the material. There are two general ways of applying the force to the steel

SCREW (INCLINE PLANE) This older method used the basic principle of the screw to adjust the space between the mill rolls. Because metal touches metal, these configurations will wear down over time and can cause quality problems.

HYDRAULIC (PANCAKE CYLINDER) This modern system uses fluid pressure to rapidly adjust the roll spacing several times per second. These minute, instantaneous adjustments allow for superior gauge tracking and higher-quality products.