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本文从文献分析得出了球铁缩松的形成机理,从机理出发得到了若干生产工艺上应遵循的原则。作者用实验部分地验证了所提出的机理,而工艺原则都在实验中得到了证实,从而归纳了一系列结论。这些结论提出了某些与当前生产上应用的完全相反的观点,主要的有:球墨铸铁虽有比较大的缩松倾向,但仍具有自身补缩的可能性;球铁可以不用冒口而消除缩松,其条件是刚度大的铸型、同时凝固、在外壳完全封闭下凝固;顺序凝固也可以消除宏观缩松,但铸件质量比不用冒口时为差;球铁铸件内除常见的宏观缩松外,在肉眼不能发现缩松的所谓“健全”部分,实际上是不健全的,其中有微观缩松;球铁的体积收缩值是一个条件性的数值,它随铸型条件不同而变;用金属型来生产球铁铸件是一个比较合适的方法。
In this paper, the formation mechanism of ductile iron was deduced from the literature analysis, and some principles to be followed in the production process were obtained from the mechanism. The author partially verified the proposed mechanism, and the principle of the process has been confirmed in the experiment, thus inducing a series of conclusions. These conclusions point to some completely contrary to current production applications. The main ones are: Ductile iron, despite its large tendency to shrink, still has its own potential for shrinkage; ductile iron can be eliminated without risking Shrinkage, the condition is a rigid mold, while solidification, the shell is completely closed solidification; order solidification can also eliminate macroscopic shrinkage, but the quality of castings without risking poor; ductile iron castings in addition to common macroscopic Shrinking, in the naked eye can not find the so-called “sound” part of the shrinkage, in fact, is not perfect, which microcosmic shrinkage; ductile iron volume shrinkage value is a conditional value, it varies with the mold conditions Change; metal type to produce ductile iron casting is a more appropriate method.