Four major performance characteristics of electric ball valve The tensile strength, plasticity and toughness of electric ball valve are lower than that of carbon steel. Although the mechanical performance of the electric ball valve is not as good as that of the steel electric ball valve, the existence of graphite endows the electric ball valve with many properties that the steel electric ball valve cannot. Such as good wear resistance, high vibration absorption, low notch sensitivity and excellent cutting performance. In addition, the carbon content of electric ball valve is high, and its composition is close to eutectic composition. Therefore, the melting point of electric ball valve is low, about 1200 ℃, and the molten iron fluidity is good. Because the volume of graphite expands when it crystallizes, the transmission shrinkage rate is small, and its casting performance is better than that of steel electric ball valve. Therefore, it is usually made of castings by casting method, so it is called electric ball valve.
Performance of electric ball valve
1. Excellent casting performance: Since the chemical composition of the electric ball valve is close to the eutectic point, the molten iron has good fluidity and can cast very complex parts. In addition, due to the large specific volume of graphite, the shrinkage of castings during solidification is reduced, which can simplify the process, reduce the stress of castings and obtain dense structures.
2. Excellent wear resistance and shock absorption of electric ball valve: the graphite of electric ball valve itself has the lubrication function, and the cavity after the graphite falls can absorb and store lubricating oil, so that the electric ball valve has good wear resistance. In addition, due to the high hardness of phosphorus eutectic in the electric ball valve, the anti-wear ability can be further improved, which is of great significance for the preparation of piston rings, cylinder liners and other friction parts. Graphite can prevent the propagation of backward motion, and gray cast iron has 10 times the capacity of eliminating exaggeration as steel.
3. Low notch sensitivity and good cutting performance: due to the existence of graphite in electric ball valves, there is almost no sensitivity to surface defects and notches when there are many small notches. Therefore, surface defects have little impact on the fatigue strength of cast iron, but its fatigue strength is lower than that of steel electric ball valves. As the graphite in the electric ball valve can play the role of chip breaking and tool lubrication, its machinability is excellent.
4. Mechanical properties of electric ball valve The tensile strength, plasticity, toughness and elastic modulus of electric ball valve are lower than those of carbon stainless steel, as shown in the table. The compressive strength and hardness of the electric ball valve mainly depend on the matrix structure. The compressive strength of the electric ball valve is generally three or four times higher than the tensile strength, which is a characteristic of the electric ball valve.