Content :

Felix accidentally saw an article about 65HRC valve spool of AAK hydraulic valve when browsing some B2B websites.

It is not the first time for AAK hydraulic valve to receive consultation on the hardness of valve spool. Some hydraulic valve manufacturers can not solve the problem of hardness because of the following reasons. First, without professional and systematic knowledge about material, how can they choose the most suitable alloy steel material? Most importantly, the heat treatment of materials is led by the processing factory, because the heat treatment is processed outside, and 20% of the factory changed the outsourcing processing place with one shot, thus, the hardness can not be guaranteed, let alone the stability.

Regarding the material for the valve spool, AAK hydraulic valve selects the most suitable steel according to the working scene of the hydraulic valve, the medium used, and the customer's hydraulic parameters, then combined them with the wear resistance, linear expansion coefficient and deformation of different steel. The High grade tool steel like Cr12MoV, 12CrNi3A, 18CrNiWA and GCr15 are our common materials, and the last and most important link in the hardness of the hydraulic flow valve spool is the heat treatment process of the steel. If the hardness needs to be above 65HRC, the carbon content of steel should be considered first, and then find a way in heat treatment. Steels with different contents have different heat treatment methods in quenching, carburizing and nitriding. Pretreatment, quenching, cold treatment, tempering, aging, fine processing and secondary aging, the aging temperature and holding time of these processes are the key. We can achieve the aging temperature of 420℃ and heat preservation of more than 10H, obtaining a hardness of 65HRC or above, which our peers can't think of or do.