With 3 Steps of heat-treated valve spool, AAK Hydraulic Cartridge Needle Valve has 2 million times of service life

China [CN]

Muhammad is from a hydraulic equipment manufacturing company in Turkey. He has been purchasing smoothly for 3 years, but stumped by the valve spool of a hydraulic cartridge needle valve. At the beginning of last year, some of their customers complained that the positioning of the paper cutter was incorrect because of the leakage of the hydraulic cartridge needle valve. The original manufacturer said that the hydraulic cartridge needle valve spool was worn due to 24H operation of the equipment, which can only be replaced every 8 months, and can only guarantee the service life of 1 million times. The boss was not satisfied with the after-sales service of the original hydraulic cartridge needle valve manufacturer and asked Muhammad to find a manufacturer with a service life of no less than 2 million times.

Muhammad left a message on AAK website: Can you customize the hydraulic cartridge needle valve with a service life of 2 million times? Especially, the valve spool shall be absolutely wear-resistant. After communication, it was learned that the original manufacturer's valve spool was out of use after 1 million times, and the boss asked him to find 3 factories to sample at the same time. This hydraulic cartridge needle valve is a standard part of HydraForce, and most hydraulic cartridge valve manufacturers have existing procedures. As long as the production process of valve spool is further upgraded, the wear resistance will be at least doubled. After 15 days, AAK sent 5 hydraulic cartridge needle valves.

Last week, Muhammad sent a PO for 600 hydraulic cartridge needle valves. Their engineers selected AAK hydraulic cartridge needle valves. In the PK among the 3 factories, AAK valve spool has the strongest wear resistance, and it is safe for 2 million times.

Because the working condition of the equipment requires high wear resistance of the valve spool, in view of this hidden danger, AAK hydraulic cartridge needle valve spool is heat treated by 3 steps:

1. First of all, the stress relief heat treatment shall be carried out by heating in stages. The heating temperature of the first stage is 380 ℃, and the heat preservation shall be 1H after reaching the temperature. The heating temperature of the second stage is 530 ℃, and the heat preservation shall be 45min after reaching the temperature. The heating temperature of the third stage is 720 ℃, and the heat preservation shall be 30min after reaching the temperature. The air cooling shall be 300 ℃, and then the air cooling shall be conducted to room temperature.

2. Secondly, carry out 2 times of quenching, heat the valve spool to 800 ℃, hold it for 2H, then immerse it in quenching oil, hold it at 65 ℃ for 40min, then cool it to room temperature, and wash and dry it. The valve spool shall be quenched for a second time, and the temperature shall be kept at 700 ℃ for 1H, and then immersed in quenching oil. Hold at 85 ℃ for 55 min, then cool to room temperature, and wash and dry.

3. Finally, place the valve spool in the tempering furnace, heat it to 420 ℃, and keep it for 30min. Continue to heat to 585 ℃, keep it warm for 1H, cool it to room temperature, and then conduct surface strengthening heat treatment, heat it to 950-980 ℃, keep it warm for 10-15min, cool it to 550-600 ℃ with water, cool it to 300-360 ℃ with oil, and finally air cool it to room temperature.

After 3 steps of upgraded heat treatment process, the strength of the hydraulic cartridge needle valve spool is increased by at least 50%, and it is quenched twice to release the residual stress. The wear resistance and corrosion resistance of the valve spool are improved, and the service life is guaranteed to be 2 million times.

AAK hydraulic cartridge needle valve, the valve spool has 2 million times of wear resistance, you can also try it!

https://www.aakindustry.com/info-detail/cartridge-needle-valves-aak468