The Processing Process of Melting and Casting Cast Iron Platform

The processing process of melting and casting cast iron platform:

The casting and grinding process of the cast iron platform strictly follows the feeding sequence: old sand new sand clay coal powder water. The mixing time is set at 6-7 minutes, and after mixing, it takes about 5 hours to mix evenly. After mixing, sieve and loosen the sand before use to make it loose and improve its permeability, flowability, etc.

Control of casting and melting process: When producing gray cast iron parts, strict control is exercised over the quality of the furnace and packaging materials, and the composition, block size, and physical and chemical functions are inspected and tested according to requirements.

Cast iron platform

Control of casting and pouring process: Before pouring, the casting water should be incubated and slag removed. During the pouring process, do not cut off the flow and ensure stability to prevent sand holes caused by sand flushing. When running the fire, it is necessary to promptly block the parts that leak casting water and replenish the casting water to reduce the disadvantages of cold insulation and insufficient pouring.

The control of the molding process is the main process for forming measuring tool castings, which directly affects the quality of cast iron platform castings. Pay attention to the following aspects:

① The operator must strictly follow the process flow for operation, and strive for the layout of measuring tool castings to make the appearance production simple and convenient, with fewer parting surfaces, draft angles, fewer sand cores, reasonable wall thickness, and transitions at the joints. Select a reasonable pouring system to allow the cast iron flat castings to solidify in batches, in order to arrange uniform measuring tool castings.

② Combining boxes is an important step that cannot be ignored. The floating sand on the surface of the mold should be cleaned and aligned according to the mark. Pay attention to the amount of wrong boxes, which is an important technique to reduce the deviation of measuring tools and castings.

③ Core placement: When placing the core, it should be smooth and the floating sand should be sorted out. The orientation of the sand core should be placed properly to prevent the occurrence of core deviation.

④ Regarding the external drying process of the dry mold, it should be operated according to the operating procedures, with a drying time of at least 8 hours to prevent the formation of sand, pores, and other defects due to incomplete drying.

After vibration peeling, there are always residual shells and oxide scales on the surface of cast iron flat plate investment casting, especially for castings with complex inner cavities, deep grooves, and blind holes, which cannot be completely cleaned. Therefore, surface cleaning is necessary. The commonly used surface cleaning methods for investment casting castings include shot blasting, sandblasting, and chemical cleaning.

For castings with complex inner cavities, deep grooves, and blind holes in cast iron platform investment casting, chemical cleaning methods are recommended, mainly including alkali boiling method, alkali explosion method, and electrochemical cleaning method. The alkaline boiling method is to heat and boil the investment casting with residual sand in a solution of caustic soda, caustic soda, or caustic soda to generate a viscous liquid of sodium silicate or potassium silicate, which separates from the casting and achieves the purpose of residual sand in the mold shell (core). It is worth noting that investment casting aluminum alloy castings must not undergo alkali boiling treatment, otherwise it will seriously corrode the surface of the casting, resulting in the scrapping of the welding platform casting.