Open-hearth furnace - equipment for the smelting of steel of a given composition and quality from iron scrap and pig iron. The open-hearth furnace got its name from the name of the inventor - the French engineer Pierre Martin, who developed it in 1864.
Technology
The key technology for the conversion of cast iron to steel is to reduce the concentration of carbon and impurities. To achieve this goal, a method is used for their selective oxidation and output to slags and gases during smelting. Steel is smelted in the following stages: melting the mixture for melting, consisting of scrap, coal, fluxes (charge), and heating the bath of molten metal. The main goal is the removal of phosphorus. The stage takes place at a relatively low temperature. The next step is boiling a metal bath. Passes at higher temperatures around 2000 degrees. The goal is to remove excess carbon. And finally, deoxidation of steel, reduction of iron oxide.
The duration of the entire smelting process is 3-6 hours; natural gas or fuel oil is used for fuel.
A few facts from the story
The converter processes of cast steel production that existed at the end of the 19th century did not allow producing large volumes of steel and providing the required characteristics. The huge reserves of cheap iron scrap accumulated by that time in industry were pushing metallurgists to search for a more productive and cheaper technology for converting iron scrap and iron to steel.
This problem was successfully solved by the hereditary metallurgical engineer Pierre Martin, who in 1864 received cast steel in a fiery furnace at a plant in French Sireil. The idea was to produce liquid steel by melting scrap and cast iron on the bottom of a reflective furnace. The success was facilitated by the use of the invention of the brothers Williams and Friedrich Simens on the recovery of heat from exhaust gases. The heat recovery method consisted in the fact that the heat of the combustion products passing through the regenerators was accumulated in the nozzles and, together with the fan air, was returned to the working zone of the furnace. The heat recovery of the combustion products allowed to increase the temperature in the furnace to the values necessary for the smelting of liquid steel.
