Steel Casting Features
1. Casting steel casting system characteristics Cast steel characteristics of high melting point, Steel Casting poor mobility, shrinkage, easy oxidation, the requirements of metal liquid fast and smooth filling.
The pouring system has the following characteristics:
⑴. Cast steel body shrinkage, casting easy to produce shrinkage, Steel Casting shrinkage, cracks and deformation defects. Thick and thick wall thickness of the castings with the principle of directional solidification set up riser system, the liquid flow through the riser into the cavity, Steel Casting to strengthen the riser of the filling capacity; for easy to produce cracks, deformation of the shell castings, The inner runner should be distributed in the thin wall of the casting and minimize the mechanical obstruction of the runner to the casting.
⑵. Cast steel casting temperature is high, Steel Casting easy to oxidize, usually using packet leakage. Leakage bagging slag effect is good, the pouring system slag effect is not high, so the pouring system cross-sectional area is large open, do not need high slag function, but should be fast and smooth full of mold. Leakage pouring pressure, easy to rush the runner, therefore, the casting system should strive to simple structure, Steel Casting strong impact resistance. Large and medium castings of the sprue and steel flow more than 1T of the runner and runner, should be composed of refractory brick. Small cast steel casting system can be used water glass, Steel Casting resin sand or all the use of sand composition, and to ensure adequate strength.
⑴. Calculate the size of the subcontract. Large quantities of small cast steel production, the commonly used subcontract pouring. Generally use closed or semi-enclosed gating system to enhance the slag capacity. Steel Casting The cross-sectional ratio of the pouring system is: ΣA: ΣA horizontal: A = 1: (0.8 ~ 0.9): (1.1 ~ 1.2)
⑵. With the size of the package to calculate the size of the package poured with the subcontract package, the leakage of molten material when pouring, basically depends on the diameter of the bottom hole. While the pouring system is to withstand the bottom of the package of molten steel, pouring system itself does not control the role of flow rate. In the actual production, it is determined that the cast steel casting system is based on the diameter of the bottom hole of the bottom of the leaked bag. Steel Casting First, from the following table 1-11, Steel Casting the bottom hole diameter and the flow rate are found at the same time, -11) Calculate pouring
Casting in the production process often occur in a variety of casting defects, how to prevent these defects, casting manufacturers have been concerned about the issue. Steel Casting This article mainly introduces some understanding and practical experience in this field.
In the long-term production, found that the main cast steel casting defects, trachoma, Steel Casting sticky sand, pores, holes, sand sand scar, swelling sand, and so on, the main production of the original wet sand casting process.
On the surface of the casting, all or part of the metal (or metal oxide) mixed with sand (or paint) or a layer of burning structure of the sand, resulting in rough casting surface, Steel Casting difficult to clean.
Sticky sand occurs in the type, Steel Casting the core surface of the strong role of the site, sub-mechanical sand and chemical sticky sand two. The mechanical sticky sand is formed by the infiltration of molten metal into the pores of the surface of the casting. Steel Casting When the infiltration depth is less than the radius of the sand, Steel Casting the casting does not form sticky sand, Steel Casting but the surface is rough. Steel Casting When the penetration depth is larger than the sand radius, Chemical sticky sand is the product of the chemical action of the metal oxide and the molding material, and is firmly bonded to the casting.