在工业的许多部门中需要大量的汽车拖拉机用的螺塞类的零件。它们或是用可锻铸铁铸造法制造,或是用型钢冷镦法制造。铸造法的生产工艺复杂,需要很大的场地和各种设备以及大量的机械加工;冷镦法需消耗贵重的型钢。在TOOCT标准中还规定可用铝合金来制造这类零件。因而,最合适的是用液态模锻法来生产。然而,现今所用的液态模锻工艺对于这类质量不大的零件是无法采用的。因为很小的一份熔融金属注入敞开的凹模后,在尚未对 Many parts of industry require a large number of plug parts for automobile tractors. They are either made from malleable cast iron or from cold heading of steel. Casting production process is complex, requiring a large site and a variety of equipment and a large number of machining; cold heading method requires the consumption of expensive steel. It is also stipulated in the TOOCT standard that aluminum alloys can be used to make such parts. Thus, the most suitable is the production of liquid die forging method. However, the liquid forging process used today is not available for such low quality parts. Because a small piece of molten metal is poured into the open die after it has not been