Sintering parts manufacturers tell you that the parts pressed with reduced iron powder are accompanied by different degrees of oxidation and decarburization during sintering, and the decarburization phenomenon increases with the severity of oxidation; iron-based parts sintered products usually have a hardness value greater than 60HB, Slight decarburization is allowed, but with the severity of decarburization, the hardness can drop to 35HB. When the decarburization is the most serious, the existence of pearlite cannot even be seen; Sintering parts manufacturers tell you that oxidation and decarburization cause sintering The surface of iron-based parts appears blue or the hardness of the product after sintering is relatively low, resulting in unqualified product appearance and performance.

There are three stages of oxidation and decarburization in the sintering of reduced iron powder parts:
1. Oxidation in the early stage of sintering
Refers to the oxidation of the compact from room temperature to before dewaxing; Sintering parts manufacturers tell you that this oxidation phenomenon usually does not see blue after the sintered product is released, the surface is rough and dull, and the hardness value does not reach the expectation.
2. Post-sintering oxidation
It refers to the oxidation of the high-temperature parts after sintering in the cooling area; in the cooling area of ​​lower temperature, the short-term oxidation only appears on the surface of the product, and the decarburization is also on the surface layer. As a result, the surface of the product turns blue, but the performance of the sintered product does not decrease. ; The manufacturer of Sintering parts tells you that if the product is oxidized in a high temperature cooling area for a long time, it will cause serious decarburization and desquamation of the product, which will seriously affect the performance of the product.
3. Mixed oxidation
Combining the first two, there are pre-sintering oxidation and post-sintering oxidation, which is also the most serious oxidation phenomenon among the three oxidations. The sintering parts manufacturer tells you that the third type of mixed oxidation occurs, not only the hardness of the product is low, but also the appearance is blue, and the phenomenon of desquamation occurs at the same time. This kind of final sintered product can only be scrapped.
Sintering parts manufacturers tell you that when sintering reduced iron powder parts, take appropriate protective measures to prevent oxidation in the early stage of sintering, and use appropriate protective gas during sintering to avoid oxidation of the sintered body in the later stage of sintering, thereby improving the success rate of sintering iron-based products.