How to repair the defects of castings
Solving method of shrinkage defects of castings, the fundamental starting point is "heat balance". The methods are as follows:
1, in the structure of machine tool castings formation of thick and hot section, a rapid solidification, artificially machine tool castings caused by the basic balance of temperature field in everywhere. By inside and outside the cold iron, local big zircon sand, using heat storage chromite sand or special coatings.
2, reasonable process design. Runner in machine tool castings in relatively thin wall place, more than the number and scattered. Take the lead in the first into the thick wall of metal liquid solidified, thin-walled place after solidification, to various basic equilibrium solidification. For machine tool castings wall thickness uniformity, with multiple internal sprue and air flow. Dispersion and all of the internal sprue, cloth, make integral heat ?