Analysis and Optimization of the Casting Process for a Ductile Iron Stand of Machine Tool
A ductile iron stand of machine tool is formed by using of manual molding of furan resin-bonded self-hardening sand and step gating system.In the original process,two risers were used to feed the shrinkages of support frame positions of the thick shaft holes at the top of the casting,but in actual production,it was found that there were slight shrinkage porosities at the roots of the risers,resulting in the casting being unqualified.After analysises of multiple schemes and numerical simulations,under the condition of keeping the other casting parameters unchanged,a riser-free casting process was attempted:the original risers were changed to wedge-shaped vent holes,the thicknesses of ingates were reduced,and external or internal chills were set near the shaft holes in order to improve the microstructure and performance of the shaft holes.At the same time,several schemes of the shaft holes being cast out or subsequently machined out were also designed and compared in production,and it was found that qualified castings could be obtained.Production practice had proven the feasibility of application of riser-free casting process in the stand castings,the molding process was simplified and the overall yield of casting was increased.
万方数据
维普
