The Development Of Iron Powder, Production Methods And Effect Of Iron Powder
Iron powder powder metallurgy is an important raw material. Industrial production and application of iron powder begins in the 1920 of the 20th century. Germany produced Carbonyl iron powder and electrolytic iron powder, mainly used as a catalyst in the chemical industry. 30 began production of powder metallurgy iron-based components. 1933 Germany developed Vortex production of iron powder by grinding. 1936 Sweden in sponge iron production from magnetite produced by reduction methods on the basis of low cost iron powder. 40 after Germany, the United Kingdom and the United States appeared iron powders by molten metal spraying, and advancing rapidly on the basis of atomized prealloyed (alloy steel, Super alloys) powder production. In 1958, China started production of iron powder by reduction methods, 60 's development of alloy and alloy powder by the spray method.
Iron powder production method, the reduction method and spray method is the main method of production. The two methods of production capacity in the world, approximately half of the total production capacity of iron powder. Electrolysis and carbonyl method is mainly used for making magnetic materials needed for high purity, fine-grained iron powder, are generally small.
Reduction method using solid or gaseous reducing agents (Coke, charcoal, anthracite, water coal gas, into natural gas, synthetic ammonia, hydrogen, and so on) reduction of iron oxides (iron ore, rolled steel scales, etc) to produce spongy iron. In the restore method, the solid carbon reduction in tunnel kiln production of sponge iron, crushed with a two-stage reduction furnace with hydrogen, h- Gan s method on the production accounts for an overwhelming majority. This reduction process as shown in figure. The longest tunnel kilns 265 meters long, annual production capacity of 65000 tonnes of iron powder. Iron powder for production of high quality iron >
98.5%, carbon 0.01%, phosphorus and sulphur are less than 0.03%, hydrogen damage of 0.1~0.2%. In addition, the United States still useful method of belt furnace for hydrogen reduction of iron scale (pyron), production of low apparent density of iron powder. Soviet useful carbon black joint and common conversion natural gas reduction of iron scale of reduction.