Fe-based powder metallurgy is a high-efficiency metal forming process that is material saving, energy saving, non-polluting and suitable for mass production. Because iron-based powder metallurgy parts are made from metal powder through pressing, sintering, machining, heat treatment and other processes, there must be certain pores in the powder metallurgy products, generally containing 10% – 30% of the pores. Compared with steel materials, it is easier to rust. So, what should we do if there is corrosion? How to prevent rust? Next, Powder Metallurgy Factory will take the iron base powder metallurgy part in the automobile gearbox – synchronizer gear hub as an example to explain the rust prevention method of iron base powder metallurgy parts for you.
Rust prevention method for production of iron-based powder metallurgy parts-synchronizer gear hub:
1. Rust prevention of iron powder: as the purchased iron powder is a powdery solid object, there will be a large number of pores between the iron powder. If wet air is injected, it will rust and agglomerate in a very short time, resulting in unusable. Therefore, the purchased iron powder is packed in a sealed thick plastic bag. At the same time, desiccant should be added inside, and thick woven bags should be used outside to facilitate lifting.
2. Iron powder storage: When iron powder is stored in the warehouse, it must be in the order of first in first out. After mixing, the iron powder shall be packed in a thick plastic bag according to the packaging method at the time of purchase and completely sealed to prevent oxidation of the mixed iron powder; They are placed on wooden pallets, and the time from use is usually controlled within 3 days.
3. Use of iron powder pressing process: in the production process of pressing synchronizer gear hub, mix iron powder as you use it. Do not take out all iron powder at one time because of many tasks. Do how much iron powder is used for pressing each shift and how much is used. Strictly control the stock of mixed iron powder between processes.
4. Storage of press blank of synchronizer gear hub: press blank of synchronizer gear hub has low strength and is easy to be damaged. It should be handled with care and placed in the plastic tray of the turnover vehicle. Within 48 hours, sintering and pressing blank can be done without additional packaging protection. If the time is exceeded, wrap and seal the turnover vehicle with plastic film to avoid the entry of moist air.
5. Three different anti-rust test methods are adopted for sintered gear hub: no anti-rust application is adopted after sintering, and 30 # engine oil is used for finishing powder metallurgy gear hub; After sintering, dip the F901 film antirust oil vertically, and use 30 # engine oil when finishing the powder metallurgy gear hub; Burn and combine, that is, dip WD40 antirust oil vertically, and use 30 # engine oil when finishing the powder metallurgy gear hub.
