Cast iron slabs are mostly made of gray cast iron or ductile iron, which must go through many links such as sand grinding, molding, melting, pouring, cleaning, and inspection. To ensure the quality of cast iron slab castings, it is necessary to control all aspects of the casting process.

 

1. Control of foundry sand grinding process

The performance of the molding sand will directly affect the quality of the gauge casting, therefore, the molding sand should have good air permeability, wet strength, fluidity, plasticity and concessions, etc.

Strictly follow the feeding sequence: old sand-new sand-clay-coal powder-water. The mixing and grinding time is set at 6-7min, and after mixing and grinding, mix thoroughly for about 5 hours. After mixing, sieve and loosen before use, so that the molding sand has Looseness to improve breathability, fluidity, etc.

 

2. Control of casting and melting process

When producing gray iron castings, the quality of man-made furnace and man-packing materials must be strictly controlled, and its composition, block size and physical and chemical properties must be inspected and accepted as required.

Inoculated cast iron is a kind of gray cast iron with flake graphite, but the manufacturing principle is different from that of ordinary cast iron, which increases the inoculation process. An appropriate amount of inoculant is added to the molten iron with low carbon and silicon content to suppress its excessive graphitization.

 

3. Control of casting molding process

Molding process control is the key process for generating gauge castings, which directly affects the quality of cast iron flat castings. Mainly pay attention to the following aspects:

1) Reasonable process: The operator must operate in strict accordance with the process, and the structure of the measuring tool casting makes the pattern manufacturing simple and convenient, so that the number of parting surfaces is small, the draft angle is provided, the number of sand cores is small, and there is a reasonable wall. Thick, there should be transition at the joint. Select a reasonable gating system to solidify the cast iron flat casting sequentially to obtain a uniform measuring tool casting.

2) Box closing: Box closing is an important link that cannot be ignored. The floating sand on the surface of the casting mold should be cleaned up, and the amount of wrong boxes should be paid attention to. It is an important means to reduce the partial box of the gauge casting.

3) Lowering the core: When lowering the core, it should be stable and clean the floating sand. The position of the sand core should be placed to prevent the occurrence of eccentric cores.

4) Drying: For the drying process of dry mold molding, it should be operated according to the operating procedures, and the drying time should be more than 8h to prevent defects such as sand and pores caused by the impermeability of drying.

 

4. Control of casting and pouring process.

Before pouring, the casting water should be inoculated and slag removed. During the pouring process, it should flow continuously and smoothly to avoid the formation of blisters caused by sand washing. When running the fire, the leaking casting water should be blocked in time, and the casting water should be replenished to prevent the formation of blisters. Reduce cold insulation, insufficient pouring and other defects.

 

cast iron slab

 

Jinggong Measuring Tools Producing Co., Ltd is specializing in manufacturing and exporting all kinds of cast iron products，especially for cast iron floor plates, cast iron surface plates, cast iron clamping plates, cast iron angle plates, cast iron box table and other machine tool castings. The products have the features of reasonable design, stable structure, superior quality and competitive price.