Resistance Wire Maintenance for electric annealing furnace

- Sep 15, 2020-

Resistance Wire Maintenance for electric annealing furnace

 

1) The oxide scale in the furnace must be cleaned up frequently with a brush, broom or compressed air to prevent it from falling on the alloy components and causing a short circuit. Generally, cleaning should not be less than once a month.

 

2) After a period of use, heat-resistant steel components such as soleplates, oranges, furnace pots, etc., it is best to lift and knock them to remove their oxide scale to avoid collapse or bury the components. Especially for chromium-manganese-nitrogen steel, the spalling is more serious in the later period.

 

3) The lower teeth of the box furnace door and the ring knife of the parallel furnace cover must be inserted into the sand seal groove tightly. The sand in the sand seal cannot be overfilled and must be level. If sand falls into the furnace, clean it up in time. For low-temperature furnaces, a layer of intact asbestos rope liner can be used.

 

4) The externally heated salt bath furnace should be lifted out of the orange vortex regularly to remove the molten salt. The condensed salt on the surface of the element can be cleaned with hot water; the condensed salt on the shelf can be removed by scraping.

 

5) The lid of the brass holding furnace must be connected tightly to prevent "copper frost" from falling into the furnace and corroding the components.

 

6) Avoid contact of non-ferrous metals such as copper, aluminum, zinc, tin, lead, etc., with electric heating elements. Whether it is a fine powder, molten liquid, or steam, the corrosion of the elements at high temperatures is very harmful. This is because the eroded part forms a "pit", the cross-section becomes smaller, and finally burns out due to overheating.

 

7) The cover plate of the trolley used for the lift-type electric annealing furnace should be tightly pressed to prevent the castings from falling into the sand during annealing to bury the components and cause overheating and melting. Therefore, it is necessary to check frequently and remove the accumulated sand in time.

 

8) Due to thermal expansion and contraction and creep elongation during heating and shutdown of the furnace, the bolts of the lead wire clamp are prone to oxidation and loosening, and should be checked and tightened regularly.

 

9) The lead-out rod hole should be blocked tightly to avoid the leakage of protective gas and burn here, causing the rod body to oxidize and peel off, resulting in poor contact between the lead-out rod and the clamp.

 

10) When a tankless carburizing furnace or a controlled atmosphere containing CO is used, carbon dissociation will occur and cause a short circuit. Therefore, the furnace door should be opened frequently or the compressed air should be used for blowing regularly, so that the carbon burning material can be burned in time.