The vacuum heat treatment electric furnace used in the experiment cannot be evacuated

The vacuum heat treatment electric furnace used in the experiment cannot be evacuated, which may be caused by various factors such as vacuum pump failure, aging or damage of vacuum seals, vacuum system leakage, vacuum pump oil problems, aging or damage of vacuum pipelines, furnace or workpiece contamination, vacuum valve failure, or misjudgment of vacuum detection instruments. The following is a specific analysis and solution:

Vacuum pump malfunction:
Reason: The vacuum pump is the core equipment of the vacuum system. If the internal components are damaged, the sealing is not tight, or the oil seal is aging, it will affect the vacuum degree.
Solution: Check the operation of the vacuum pump, clean or replace damaged components, ensure good sealing, and regularly replace the oil seal.

Aging or damage of vacuum seals:
Reason: Aging of seals, damage to sealing surfaces, or loosening of fixing screws can all lead to gas leakage, thereby reducing the vacuum level.
Solution: Check and replace seals, reassemble components, and perform seal checks at critical locations such as furnace doors, electrodes, and thermocouples.

Vacuum system leakage:
Reason: There may be leakage points in the vacuum system, such as rubber ring seals, welds, vacuum pipeline connections, etc.
Solution: Use static pressure boosting method to determine the leakage location, that is, close the vacuum valve, separate the pumped container from the pump, and observe the pressure change over time. By analyzing the pressure time curve, identify the dominant factor of air leakage and take corresponding measures, such as tightening the bolts at the connecting flange and replacing the sealing film.

Vacuum pump oil issue:
Reason: The selection and use of vacuum pump oil are crucial for the vacuum degree. If the oil is selected improperly or not replaced regularly, the moisture and impurities in the oil can cause a decrease in vacuum degree.
Solution: Choose the appropriate vacuum pump oil and replace it regularly. At the same time, regularly clean the filter screen to prevent blockage from affecting the vacuum degree.

Aging or damage of vacuum pipeline:
Reason: Aging or damage to the vacuum pipeline can also cause gas leakage, thereby reducing the vacuum degree.
Solution: Check and replace aging vacuum pipelines to ensure tight and leak free connections.

Furnace or workpiece contamination:
Reason: During the processing, the furnace body or workpiece may produce gases, impurities, or moisture, which can affect the vacuum degree.
Solution: Keep the tooling and parts clean and dry before processing to prevent residual impurities from entering the furnace. Regularly clean the residual materials in the furnace and keep it clean.

Vacuum valve malfunction:
Reason: Vacuum valves may have poor sealing due to worn sealing surfaces, faulty drive mechanisms, or improper installation.
Solution: Grind the sealing surface of the valve or replace the sealing ring, check whether the pressure or voltage of the driving mechanism is normal, and clean the rust or impurities on the surface of the piston in the cylinder. When reinstalling the valve, a level should be used for calibration to ensure that the valve axis is concentric with the furnace interface.

Vacuum detection instrument misjudgment:
Reason: Vacuum degree detection instruments are key equipment for determining the vacuum degree of vacuum heat treatment electric furnaces. If the testing instrument is damaged or improperly calibrated, it can lead to misjudgment.
Solution: Regularly inspect and maintain testing instruments to ensure their accuracy and reliability. If there is suspicion of misjudgment by the testing instrument, a standard vacuum gauge can be used for comparative testing.