These defects were eliminated and the sound castings with steady quality were obtained by adopting cooling-hardness resin sand and setting chilled iron as well as controlling the production process.

• 采取改用冷硬树脂砂造型、安放冷铁和搞好生产过程的质量控制等措施,基本上消除了这些缺陷,获得了质量稳定的合格铸件。