一、前言近年来,球墨铸铁的进展是惊人的,並正打算将它作为低温材料来应用,例如,对具有低温韧性的高Ni系奥氏体基体球铁进行了研究。以前如液化天然气装登等在极低温度下工作的工程材料,多数采用铸造不锈钢,但随着制品形状的复杂化,铸造性能良好的、在低温 I. Introduction In recent years, the progress of ductile iron is amazing, and it is intended to be used as a low temperature material, for example, the high Ni austenitic matrix ductile iron with low temperature toughness was studied. In the past, such as liquefied natural gas loading board work at extremely low temperature engineering materials, the majority of cast stainless steel, but with the complexity of the shape of the product, good casting performance, low temperature