Steam treatment process in powder metallurgy process

In the powder metallurgy process, for it is refrigeration compressor steam treatment on the sealing process and increase the tightest, namely the powder metallurgy parts placed in a heating furnace at a certain temperature, certain amount to pass into the furnace in the supersaturated water vapor, in part around the existence of a large number of water vapor.

Those who come into contact with the surface of the steam iron atoms, including the outer surface and the inner surface of the connected voids occurs, oxidation reaction, generating a layer of oxide film, the main component of this layer of oxide film is Fe3O4, Fe3O4 is a body centered cubic system, the density of 5.16g/ cm3, the Fe3O4 of iron than the volume ratio, the internal parts of the connectivity gap closed, achieve the purpose of sealing parts, increase air tightness.

Due to the oxide film and cover in the parts of the substrate surface, very dense and strong adhesion, resulting in the environment of water vapor and corrosive medium is difficult to enter the parts inside, to reach a good anti rust function. Due to the high hardness of Fe3O4 and Rockwell hardness of pure Fe3O4 around 50HRC, processing parts of the apparent hardness reaches more than 60HRB, is helpful to improve the base parts surface hardness, wear resistance, anti abrasion, tensile strength can also be improved, steam treatment, the tensile strength of iron base materials increased 40-50%.