As thermal equipment for smelting, roasting, sintering, melting, heating and other processes of materials or workpieces, relatively complete copper smelting furnaces have appeared in China as early as the Shang Dynasty in industrial furnaces, and the furnace temperature can reach 1200 °C. During the Spring and Autumn Period, with the development of technology to increase furnace temperature, cast iron appeared at that time.Influence of Vacuum Carburizing and Quenching on New Gears In 1794, a straight cupola for melting cast iron appeared in the world. Then, in 1864, on the basis of Siemens (England) regenerative furnace principle, Martin (France) built the first steelmaking open hearth furnace heated by gas fuel. Through the high temperature preheating of air and gas in the regenerator, he made the furnace temperature reach the temperature above 1600 ℃ required for steelmaking.Vacuum Heat Treatment of Vacuum Carburized Alloy Steel Gear By the 1920s, the supply of electric energy was gradually sufficient, and various resistance furnaces, electric arc furnaces and cored induction furnaces were used in industry to achieve a wide range of applications. At the same time, the emergence of mechanized and automated furnace types has increased furnace productivity and improved working conditions to a certain extent.HORIZONTAL MITRE BAND SAW MACHINE BS-460G In the 1950s, coreless induction furnaces developed rapidly. Later, electron beam furnaces appeared, which use electron beams to impact solid fuels, which can enhance surface heating and melt materials with high melting points.HORIZONTAL MITRE BAND SAW MACHINE BS-460GB