Features: long castings are prone to deformation, such as machine bed, cylinder block and cylinder head of diesel engine. Due to too much difference in wall thickness of castings and uneven cooling, castings are prone to deformation. Some castings are deformed after processing and storage for a period of time.
(1) For some castings prone to deformation, in addition to properly increasing the machining allowance, the mold can also be made into reverse deformation (such as making the mold into reverse bending) to correct the deformation of the castings.
(2) The castings shall be subject to stress relief annealing to eliminate the internal stress of the castings. If the conditions permit, aging treatment can be adopted. Do not open the mold too early, and do not stack the castings after sand falling.