Classification of iron i. Overview 1. Definition and application of ferroalloy. Ferroalloy is an alloy of iron and one or more metallic or nonmetallic elements. Ferroalloy is one of the main raw materials for steelmaking and mechanical casting, and is used as deoxidizer, desulfurizer and alloy additive in steelmaking and casting. 2. Classification of ferroalloys. There are many varieties of ferroalloys, which are generally classified according to the elements they contain. (1) ferrosilicon: industrial ferrosilicon-ferrosilicon-poor ferrosilicon (12% silicon) ferrosilicon-aluminum alloy (2) ferromanganese: high carbon ferromanganese (7% carbon) medium carbon ferromanganese (1.0 carbon) ferrochromium: high carbon ferrochromium (carbon content 4 Here is a brief introduction to you: the rolling process with rolling temperature above the recrystallization temperature of metal is called hot-rolled stainless steel plate, and the rolling below the recrystallization temperature of metal is called cold-rolled stainless steel plate. Rolling is divided into cold rolling and hot rolling, with recrystallization temperature as the distinguishing point. Cold rolling is generally used to produce strip, and its rolling speed is relatively high. The temperature of hot rolling is similar to that of forging. Cold-rolled plates are cold-rolled, and ordinary steel plates are made of ordinary carbon structural steel or low-alloy structural steel. The surface quality of cold-rolled plate is good. Has good stamping performance. It is required to ensure that cold bending and cup test are qualified, and it is often used as raw material for automobile and other industries and coated plates. Cold-rolled high-quality steel plate: it mainly includes all kinds of high-quality steel cold-rolled steel plates, the most commonly used is carbon structural steel plate, especially cold-rolled steel plate for deep drawing, which is made of low-carbon high-quality steel 08Al, and the steel plates are divided into three groups according to surface quality; Ⅰ, Ⅱ and Ⅲ represent specially advanced, advanced and advanced finish surfaces respectively. According to the drawing level, it is divided into ZF, HF and F levels (representing the most complicated, complicated and complicated parts for stamping), and according to the allowable deviation of steel plate thickness, it is divided into A and B levels, which are widely used in automobile and tractor industries. Hot-rolled products of hot-rolled plates have excellent properties such as high strength, good toughness, easy processing and forming, and good weldability, so they are widely used in shipbuilding, automobiles, bridges, construction, machinery, pressure vessels and other manufacturing industries. 2. About pig iron and tinplate pig iron is an iron-carbon alloy with carbon content exceeding 2%. Industrial pig iron generally contains 2%-4.3% carbon and contains elements such as C, SI, Mn, S and P, which is the product of iron ore smelting in blast furnace. According to the different forms of carbon in pig iron, it can be divided into steelmaking pig iron, casting pig iron and ductile iron. Properties of pig iron: pig iron is hard, wear-resistant and castable, but fragile and cannot be forged. Properties, Introduction and Uses of Various Pig Iron The carbon in pig iron for steelmaking mainly exists in the form of iron carbide, and its cross section is white, usually called white iron. This kind of pig iron is hard and brittle, and is generally used as a raw material for steelmaking. Carbon in cast pig iron exists in the form of flake graphite with gray fracture, which is usually called gray cast iron. Because graphite is soft and has lubricating effect, cast iron has good machinability, wear resistance and castability. But its resistance is not enough to forge and roll, and it can only be used to make various castings, such as casting various machine tool beds and iron pipes. Carbon in nodular cast iron exists in the form of spherical graphite, and its mechanical properties are far superior to those of gray cast iron and close to steel. It has excellent casting, cutting and wear resistance, and has certain elasticity, and is widely used to manufacture advanced castings such as crankshafts, gears, pistons and various mechanical parts. In addition, there are pig iron with particularly high content of silicon, manganese, nickel or other elements, which are called alloy pig iron, such as ferrosilicon and ferromanganese, and are often used as raw materials for steelmaking. Adding some alloy pig iron in steelmaking can improve the properties of steel. Tinplate, in which Sn is the coating, also called tinplate (note the difference between white iron, zinc and iron, in which Zn is the coating, which is the common name of galvanized iron). Tinplate is a common name of tinplate, abbreviated as SPTE, which refers to cold-rolled low-carbon steel plate or steel strip with commercial pure tin on both sides. Tin mainly plays an anti-corrosion and anti-rust role. It combines the strength and formability of steel with the corrosion resistance, weldability and aesthetics of tin, and has the characteristics of corrosion resistance, non-toxicity, high strength and good ductility.