Numerical simulation for casting process may optimize craft design, shorting trial cycle, cut the cost, decrease castingdefect and assure the casting quality.
铸造过程的数值模拟可以优化工艺设计，缩短产品试制周期，降低成本，减少铸件缺陷，确保铸件质量。
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The results showed that the root reason for valve body failure was seriously castingdefect exist and its big and density shrinkage porosity form the original crack;
The results show that the partial unmelted region, castingdefect structure and secondary crack form in the welding seam, which result in the low stress breakage of the samples.