In the process of Ni hard cast heat treatment, due to its obtained martensite as cast, so in the production of nickel hard casting metal casting. Because the best use in metal mold casting, cooling speed, can effectively inhibit austenite pearlite transformation, and can avoid the graphitization, guarantee purpose white cast iron, because the cooling speed, the primary crystallization of fine microstructure, mechanical performance is much higher than that of sand casting.
For the simple shape of Ni hard cast, especially thick Ni hard cast iron parts, such as roller, roller head, grinding ball of wet ball mill lining plate, etc., should be used in metal casting casting method such as possible, also known as die casting, in the operation of the process in the liquid metal will be effective poured into the metal casting, the casting method of casting.
Advantages of metal casting for nickel hard castings
1. the castings made of metal hard nickel castings have higher mechanical properties than sand mold castings. Similarly, the tensile strength of the alloy is increased by about 25%, the yield strength is increased by about 20%, and its corrosion resistance and hardness have also been improved significantly.
2. the precision and surface finish of the machined nickel hard castings are higher than that of the sand castings, and the quality and size are stable.
3. the production rate of the casting is high, the consumption of liquid metal is reduced, and it can save 15 ~ 30%. in general.
4. without sand or less sand, it is generally possible to save plastic materials from 80 to 100%.http://www.wuxiorient.com/