Metallic Materials is one of piping materials that Piping & Fabrication will expose today, and with this post I hope we all know what is Metallic Materials on Piping Materials.
Metals are divided into two types: ferrous, which includes iron and iron-base alloys; and nonferrous, covering other metals and alloys. Metallurgy deals with the extraction of metals from ores and also with the combining, treating, and processing of metals into useful engineering materials. This section presents the fundamental metallurgical concepts and practices associated with the most common engineering metals, and outlines metallurgical considerations appropriate in the selection process of metals for piping system construction.
Ferrous Metals
Metallic iron, one of the most common of metals, is very rarely found in nature in its pure form. It occurs in the form of mineral oxides (Fe2O3 or Fe3O4), and as such it comprises about 6 percent of the earth’s crust. The first step in the production of iron and steel is the reduction of the ore with coke and limestone in the blast furnace. In this process, the oxygen is removed from the ore, leaving a mixture of
iron and carbon and small amounts of other elements as impurities. Coke is the reducing element and source of heat. The limestone (CaCO3) acts as a fluxing agent which combines with impurities of the ore in the molten state and floats them to the top of the molten metal pool, where they can be removed as slag. The product removed from the blast furnace is called pig iron and is an impure form of iron containing about 4 percent carbon by weight percent. Liquid pig iron cast from the blast furnace is sometimes used directly formetal castings. More often, however, the iron is remelted in a cupola, or furnace, to further refine it and adjust its composition.
Cast Iron
Pig iron that has been remelted is known as cast iron, a term applicable to iron possessing carbon in excess of 2 weight percent. Compared with steel, cast iron is inferior in malleability, strength, toughness, and ductility. On the other hand, cast iron has better fluidity in the molten state and can be cast satisfactorily into
