Electric Arc Furnace

Electric arc furnaces are giant pots that melt steel. They enable the recycling of scrap steel. Recycled steel both costs far less than creating steel from raw materials and has a lower environmental impact.

The process involves three-phase electrodes which create an arc that reaches about 3000°C (5400°F).

Frenchman Paul Héroult (co-inventor of aluminum smelting) perfected using electricity to melt iron. Eventually, he licensed his arc furnaces to US Steel and Halcomb Steel Company. Arguably, Siemens 1857 regenerative furnace and Moissan’s 1892 furnaces are predecessor technologies.

In a familiar pattern, Heroult invented the arc furnace in France but commercialized it in the US. Most furnaces were installed at US Steel.

Undoubtedly, electric arc furnaces always had some utility. Eventually, they became vastly more profitable when combined with the Nucor Mini-Mill innovation.

High Strength, Mass Produced Steel (Bessemer Steel)

Vastly increased the quality and decreased the price of steel. Unlike the iron furnaces, that created small amounts of high strength iron, the Bessemer process created enormous amounts of much stronger steel. The Bessemer process is still in use today.

On Aug. 24, 1856, Bessemer described the process of forcing air through steel that dramatically increased the strength of the steel, creating modern steel.

His steel-making company did well and he was eventually rewarded financially and given a knighthood.

Besides making steel stronger Bessemer’s process also dramatically decreased the price of steel. Over time, prices reduced by an order of magnitude from 1873 to 1893.

American William began similar experiments years before Bessemer, in 1847. However, he lacked the finances to prove and patent his method.