Basic operation process of steel production

Heat treatment ( 热处理) - Is the use of heating and cooling to change metal rational qualitative approach. Heat treatment can improve the microstructure of steel, the physical requirements needed for reach. Toughness, hardness and wear resistance is several of secure features by heat treatment. To get these features, need to use the hardening heat treatment & lt; Also known as quenching & gt; , tempering, annealing & lt; Also called 朡 & gt; And surface hardening operation. Hardening ( Hardening and Hardening) - Is the metal evenly heating to proper temperature, and then quickly immersed in water or oil quenching, or in the air or frozen area of cooling, needed to make metal hardness. Temper - Steel after hardening will become fragile, stress caused by the quench hardening and at the same time, can make the steel tap and rupture. To eliminate the brittle, usable and tempering treatment. Tempering is the steel back of heating to proper temperature or color, and then quenching. Although tempering to slightly reduce the hardness of steel, but can increase the toughness of the steel and decrease the brittleness. Annealing - Annealing is to eliminate the inner stress of steel and steel method. Annealing method is heat the steel above the critical temperature, and then put into the dry ash, lime, asbestos or enclosed within the furnace, to make it slowly cooling. Hardness ( 硬度) - Is a material resists the external things into a kind of ability. Test steel hardness is the most common method is to use a file on the edge of the workpiece on the file, by its surface scratch depth is presented to determine the hardness of high and low. This method is called file test this method is not scientific. Very accurate with the hardness tester to test, it is modern test hardness of the commonly used method. The most commonly used test method with rockwell hardness test of diamond into the metal rockwell hardness testing machine to measure the depth of the hardness of the metal, into the greater the depth, the smaller the hardness. Diamond into the depth of the metal, but from the pointer points to the correct number, the number is called the rockwell hardness number. Forging - With a hammer to make metal certain shape & lt; Molding & gt; Method, when the steel is heated to forging temperature, can be engaged in forging, bend flexion, smoked pull, molding operation. Most of the steel are easily when heated to a bright fuchsia forging. Brittle - Said the nature of the metal is easy to rupture, the brittleness of cast iron, and even fell on the ground will burst. There is a close relationship between hardness and brittleness, high hardness materials are usually brittle also big. Ductility - ( Also known as softness) Is not broken by external force permanent deformation of metal properties of ductile metal can take out into a thin line. Elastic - Is from external metal deformation, when the external force to eliminate back to its original shape after a kind of nature. Spring steel is a kind of elastic material. Hardness - Is a metal to resist external things Pierce or cutting a can increase the hardness of the commonly used method is quenched steel. Malleable - Is also called malleability, ductility of metal or softness of another kind of representation. Is malleable metal hammer forging or rolling and deformation from rupture of a nature. Toughness is the ability of metal by vibration or impact. Ductile and brittle opposite.