Large machine bed castings

Large machine bed castings,also known as large castings,need to be inspected before painting.Tools should be used to repair uneven surfaces,and any dirt on the surface should be removed.

Large machine bed castings are manufactured according to the standard GB9439-88.

①The bed casting and shock absorption are good,as graphite in cast iron is beneficial for lubrication and oil storage.Similarly,due to the presence of graphite,the seismic resistance of gray cast iron is better than that of steel.

②Good process performance.Due to its high carbon content and near eutectic composition,gray cast iron has a lower melting point,good flowability,and low shrinkage rate,making it suitable for casting complex or thin-walled bed castings.In addition,due to the tendency of graphite to form chips during cutting,the machinability of gray cast iron is better than that of steel.

The advantages of using resin sand molds to cast large machine bed castings:

Polystyrene foam molding is used in the production of full mold casting,and furan resin self hardening sand molding is applied.When the molten metal is poured into the mold,the foam plastic pattern will vaporize under the action of the high-temperature molten metal,burn and disappear,and the molten metal will replace the position occupied by the original foam plastic,cooling and solidifying into a bed casting with the same shape as the pattern.

Compared to traditional sand molds,large molds such as machine tool bed castings have great advantages.They not only save expensive wood mold costs,but also are easy to operate,shorten production cycles,improve production efficiency,and have advantages such as small size,small machining allowance,and good surface quality.

The production of large machine tool bed castings has good shock absorption performance because the graphite in cast iron is conducive to lubrication,so it is good;Due to the presence of graphite,the seismic resistance of cast iron is better than that of steel parts.The process performance of bed castings is good.Due to the high carbon content of gray cast iron,which is close to the eutectic composition,the melting point is relatively low,making it suitable for casting structurally complex or thin-walled castings.

The advantages of using resin sand molds to cast large machine bed castings:

1、The resin sand mold has good stiffness,and in the early stage of pouring,the sand mold has the conditions to utilize the graphite expansion during the solidification process of cast iron,as well as the defects of ground shrinkage and porosity,to achieve less riser and no riser casting of gray cast iron and ductile iron parts.

2、Polystyrene foam molding is used in the production of full mold casting,and furan resin self hardening sand molding is applied.When the molten metal is poured into the mold,the foam plastic pattern will vaporize under the action of the high-temperature molten metal,burn and disappear,and the molten metal will replace the position occupied by the original foam plastic,and will be cooled and solidified into a full mold casting with the same shape as the pattern.

3、Relatively speaking,lost foam casting has significant advantages over traditional sand molds in producing single or small batches of automotive panels,large machine bed castings,and other large molds.It not only saves expensive wood mold costs,but also facilitates operation,shortens production cycles,improves production efficiency,and has advantages such as small size,small machining allowance,and good surface quality.

Characteristics of Large Machine Tool Bed Castings:

(1)Good seismic resistance.Due to the advantage of graphite in cast iron for lubrication and oil storage,it is beneficial.Similarly,due to the presence of graphite,the seismic resistance of gray cast iron is better than that of steel.

(2)Good process performance.Due to its high carbon content and close to eutectic composition,gray cast iron has a relatively low melting point,good fluidity,and low shrinkage rate,making it suitable for casting structurally complex or thin-walled castings.In addition,due to the tendency of graphite to form chips during cutting,the machinability of gray cast iron is better than that of steel.