The Basic Information Of Iron Powder
Iron Powder The basic information of iron powder, ron powder size of less than 1mm iron particles aggregates. Colour: Black. Is the main raw material of powder metallurgy. According to the particle size, customary is divided into coarse powder, medium powder, fine powder, fine powder and ultrafine powder five grades. The iron powder having a particle size in the range of 150 to 500 μm is a coarse powder having a particle size of 44 to 150 μm, a fine powder of 10 to 44 μm, a fine powder of 0.5 to 10 μm, an ultrafine powder of less than 0.5 μm, powder. Will generally be through the 325 mesh standard sieve is less than 44μm particle size known as the sub-sieve powder, to be more accurate screening can only use gas flow classification equipment, but for some easy oxidation of iron can only use JZDF Nitrogen protection classifier to do. Iron powder mainly includes reduced iron powder and atomized iron powder, which are named for different production methods
Iron Powder Since the early 1930s iron powder began to be used in the powder metallurgy industry, there have been many iron production methods. Due to technical and economic reasons, many of which have never been beyond the experimental or pilot stage, such as with hot hydrogen
Other methods such as the Hametag Process, the aqueous solution electrolysis, the fluidized bed hydrogen reduction process, the rotating disk atomized liquid steel method (D.P.G. Process, air atomized liquid pig iron (R.Z.Process) and the combined reduction of natural gas and solid carbon, etc., have gone through relatively short-term industrial applications, and then due to other more competitive methods and no longer Used for industrial production of iron powder. As for the iron powder produced by the carbonyl method (see carbonyl powder method), because of its fine particles, it is expensive, does not apply to sintered mechanical parts and welding electrodes; but its high purity, special particle structure, showing excellent performance.
Iron powder production process is now dominated by the iron ore production process is: iron oxide reduction process of the Hingnas method and the Pine method, low carbon steel liquid water atomization method, belonging to high purity pig shot peening and decarburization The QMP method of the process and r) omfel% 26bull; Which Hergus law and water atomization of iron powder production has overwhelming advantage.
Hoganas Process is a solid carbon-hydrogen two-step reduction process developed by Hoganas, Sweden. The iron ore concentrate (total iron content) was mixed with low-sulfur coke-limestone powder (used for desulfurization). The mixture was packed in the SiC reduction vessel. The tunnel kiln is heated to about 1200 ° C to reduce the slag to sponge iron. The sponge iron is crushed into less than 0.175 mm (-80 mesh) or less than 0.14 mm (-100 mesh) and then applied to a steel belt reduction furnace for reduction annealing at 800 to 900 ° C with decomposed ammonia. After annealing the sintered powder block to hammer broken, you can get high-quality sponge iron powder.
Pyron Process (Pyron Process) will be low-carbon steel rolling steel scale broken to less than 0.147mm, placed in a multi-bed baking furnace at 980 ℃ oxidation of Fe2O3. And then the Fe2O3 powder fed to the belt furnace, the temperature does not exceed 1050 ℃ through the hydrogen to reduce it to iron powder.
Iron Powder Low-carbon steel liquid water atomization Low-carbon scrap through the molten slag to remove or reduce phosphorus, silicon and other impurity elements, through the leak into the atomizer, while spraying high pressure (about 8.3MPa) water flow crushing metal flow Into the liquid droplets, droplets fall into the bottom of the sink cooling and solidification into powder. Powder by magnetic separation, dehydration and drying, into the belt furnace, at 800 ~ 1000 ℃ to decompose ammonia to be reduced annealing treatment, that is, high purity water atomized iron powder.
The QMP method was developed by Quebec Metal Powder, Canada. The high-purity molten molten iron (about 3.3% ~ 3.8% carbon) is injected into the leak packet, and the molten iron flowing from the leakage nozzle is crushed into the granulated (about 3.2mm) by the high-pressure water jetted horizontally, Air in a water-cooled container, so that part of the oxidation. The dried iron particles are pulverized by ball milling, and then the powder sieved to less than 0.147 mm is fed into a belt furnace having a decomposed ammonia gas and subjected to decarburization annealing at 800 to 1040C using oxygen contained in itself , And then decomposition of ammonia gas reduction annealing, you can get powder metallurgy with iron powder.