一、概况由６人组成的考察团于１９９７年５月１３日至６月２日在美国进行了以球铁生产及球铁热处理工艺和设备为重点内容的考察。本次考察的铸造厂，基本上是以生产汽车球铁件为主，其生产的概况综合统计在下表内。尽管这些工厂在生产技术与设备的先进程度上有所差别，但... I. Overview An investigation team composed of six people conducted a survey focusing on ductile iron production and ductile iron heat treatment technology and equipment in the United States from May 13 to June 2, 1997. The foundry of this study, basically based on the production of automotive ductile iron pieces, the general statistics of their production in the table below. Although these plants vary in the sophistication of production technology and equipment, ...