The Marten furnace and its importance in the production of steel

The main melting unit in steelmakingproduction is open-hearth furnace. It is intended for the smelting of steel with a specified chemical composition and with certain physical and mechanical characteristics. The Marten furnace, which survived several industrial and technological revolutions, allows melting the most complex steel grades, including alloyed ones.

The open-hearth furnace of the open-hearth type is a flaming reflecting unit of the regenerative principle of action, consisting of the following structural elements:

• The working space, which includes the back and front walls and arch.
• Heads with vertical channels, through which the fuel and air mixture are supplied to the working chamber and the combustion products are withdrawn from it.
• Gas and air slag, designed to collect and accumulate large fractions of melting dust.
• Regenerators to ensure a constant temperature regime by heating the gas fuel and air mixture with the heat of the residual combustion products that leave the working chamber.
• The system of reversible reversing-regulating valves, designed to change the direction of supply of gas fuel and air mixture into the working space, and also to remove combustion products from it.
• Heat recovery boiler.
• Chimney.

The Marten furnace is symmetricalaggregate, which implies the same design of its right and left parts relative to the vertical axis. Loading of raw materials is carried out through special openings - filling windows, closed by bolts, which are thick steel plates. On the rear wall of the unit there is an outlet, through which the finished steel merges into the bucket. During melting, the outlet is clogged with a weakly caking refractory clay, which is knocked out when the finished melt is released.

The Marten furnace allowsalmost all types of carbon steels and many grades of alloy steel. But the use of various charge materials, necessary for the open-hearth process, saturates the molten metal with a significant amount of harmful impurities. Even a tiny fraction of such additives as sulfur, phosphorus, arsenic and some other elements contribute to a sharp deterioration in the physico-chemical properties of steel, reduce the plastic qualities of the metal, and give it an excessive fragility.

For smelting high-quality grades of steelan electric arc furnace is intended. The whole history of the development of machine building and metallurgy boils down to a struggle for the qualitative characteristics of metals, the improvement of their mechanical, physical and chemical properties. And the secret of the highest quality of metal lies in its chemical purity. Electrometallurgy helps to get chemically pure, and therefore, high-quality metals and alloys. The bulk of alloyed high-quality steels is smelted in electric arc furnaces.