The casting process of machine tool bed casting is very delicate, especially the temperature is particularly delicate, so in the end what are the essentials to be noted by the operator? The following is my introduction to the machine tool bed casting casting casting process:.
In production, pouring should follow the principle of high temperature out of the furnace, low temperature pouring. Because the increase of the metal liquid furnace temperature is conducive to the thorough melting of inclusions, slag floating, easy to clear slag and gas, reduce machine tool castings slag and porosity defects; using a lower pouring temperature, it is conducive to reduce the dissolution of gas in the metal liquid, liquid shrinkage and high temperature metal liquid baking on the surface of the cavity, to avoid the production of porosity, sticky sand and shrinkage and other defects. Therefore, under the premise of ensuring the cavity is filled, try to use a lower pouring temperature.
The process of injecting the metal liquid from the casting ladle into the mold is called pouring. Improper pouring operation will cause under-pouring, cold space, porosity, shrinkage and slag and other machine tool casting defects, and cause personal injury.
In order to ensure the quality of machine tool castings, improve productivity and to achieve safe production, pouring should strictly comply with the following operating principles.
(1) pouring package, pouring tools, furnace pre-treatment of breeding agent, spheroidizing agent, etc. must be fully dried before use, after drying before use.
(2) The pouring personnel must wear working clothes and protective glasses as required, and the workplace should be free from obstruction. The metal liquid in the pouring ladle should not be too full, so as not to overflow and injure people when conveying and pouring.
(3) The correct choice of pouring speed, that is, the beginning should be slow pouring, to facilitate the alignment of the gate, reduce the impact of molten metal on the sand and facilitate gas discharge; then fast pouring, in order to prevent cold isolation; almost full before pouring and should be slow pouring, that is, follow the principle of slow, fast, slow.
(4) for liquid shrinkage and solidification shrinkage is relatively large machine tool castings, such as medium and large cast steel parts, pouring in time from the gate or riser to fill the pouring.
(5) pouring should be promptly cast in the gas bubble ignition paragasms, so as not to produce pores due to the cast holding air, as well as incomplete combustion of gas and damage to human health and pollution of the air.