负压冷冻铸型铸造及其铸件特性

Reduced-pressure Frozen Mold Casting Method and Casting Characterization

现在,铸造工厂存在着环境恶化,工业废弃物多,用于环保的设备及其运行费用高,作业条件恶劣,青年工人来源短缺等问题。冷冻铸型铸造法是一种造型新方法,只用石英砂和水制作铸型,让其在冷凝室中冻结成型。其优点有:浇注后铸型自然溃散,落砂容易;型砂不用像以往的砂铸型一样进行再生处理;环保设备投资少;作业环境得到改善。然而至今,有关负压冷冻铸型铸造法的铸型及铸件特性的详细报道尚少,技术上有诸多不明之处。研究将铸造铝合金,铸铁(灰铁,球铁),铸钢等金属液浇入各种状态的负压冷冻铸型中,测量金属液流动状态,温度及铸型的气压特性,对方法进行评价。结果表明,负压冷冻铸型的特性与传统的砂铸型没有太大的差异,但在金属液流动及铸型排气方面见优,有望适用于各类铸件的生产。

Aimed at the problems in casting industry,such as environmental deterioration around plants, generation of industrial waste, high cost of establishing environmental sound facilities, and difficulty in securing young workers because of very poor working conditions, and so on, a new process of reduced-pressure frozen molds was put forward. In the process, the casting moulds are prepared simply by freezing silica sand and water in a freezer under reduced pressure. The adcantages of the process are as follows： the mold spontaneously disintegrates after molten metal is poured; shakeout is easy; the reuse of sand is possible without the need for a regeneration treatment; equipment investment for environmental protection is small; and the working conditions are excellent. However, detailed reports concerning the characteristics of reduced-pressure frozen molds and their casting performance are scarce, and there are numerous aspects that are still technically unclear. In this study, aluminum alloy, cast iron（FC molten metal, FCD molten metal）, and cast steel were poured into reduced-pressure frozen molds and an evaluation was performed based on fluidity, thermal and gas pressure measurements of the mold and molten metal. As a result, it was shown that there were basically no big differences between the characteristics of the reduced-pressure frozen molds and those of conventional molds. It was also clarified that the fluidity and degassing characteristics were superior and application of such molds to various cast products would be possible.