The main way of pumping valve castings in the process of heat treatment is annealing, and the annealing is also divided into graphitization annealing and stress relief annealing.
1. Graphitization annealing: Graphite castings are graphitized and annealed to reduce hardness, improve processability, and improve the ductility and toughness of cast iron.
2. Stress relief annealing: In order to eliminate the residual stress of the casting, stabilize its geometry, reduce or eliminate the distortion caused by the cutting process, the casting needs to be subjected to stress relief annealing.
Pump valve casting quality requirements
1. The chemical composition and mechanical properties of the pump body material are in full compliance with the relevant material standards.
2. The deviation of the shape and size of the Pump valve castings is in accordance with the provisions of its drawings.
3. The non-machined surface of the Pump valve castings should be smooth, smooth, non-sticky, non-oxidized, non-porous, free of sand, and free of cracks.
4. The connection of each part of the pump valve casting should be firm and there is no looseness.
5. The results of the pump valve casting pressure test and the sealing performance test meet the requirements of the relevant test standards.www.dmgcastings.com