在考虑锻造工艺时特别是后一火的锻造时，应尽量避免在临界变形程度下进行，以免得到粗大晶粒***。具体来说，高温下金属塑性好，变形抗力小，应采用远大于临界变形程度的较大变形量锻造；低温修正时采用低于临界变形程度的小变形量进行局部修整。

When the forging process is cidered, especially when the last fire is forged, the critical deformation should be ***oided as far as , so as to ***oid coarse grain structure. Concretely speaking, high temperature metal has good plasticity and ***all deformation resistance. We should adopt large deformation amount forging far greater than critical deformation degree. When low temperature correction is used, ***all deformation below critical deformation degree should be used for local trimming.

锻造设备是指在锻造加工中用于成形和分离的机械设备。锻造设备包括成形用的锻锤、机械压力机、液压机、螺旋压力机和平锻机，以及锻造操作机、开卷机、矫正机、剪切机、等辅助设备。

Forging equipment is the mechanical equipment for forming and separating in forging. Forging equipment includes forging hammer, mechanical press, hydraulic press, screw press, forging machine, forging machine, coiler, straightening machine, shearing machine, and other auxiliary equipment.

锻造工艺过程一般由以下工序组成，即选取钢坯下料、加热、成形、锻后冷却。锻造的工艺方法有自由锻、模锻和胎膜锻。生产时，按锻件质量的大小，生产批量的多少选择不同的锻造方法。

The forging process is generally of the following processes, namely, the selection of high quality billets, heating, forming and cooling after forging. The forging process includes free forging, die forging and fetal membrane forging. When manufacturing, according to the size of forgings and the number of production batches, different forging methods are chosen.

自由锻生产率低，加工余量大，但工具简单，通用性大，故被广泛用于锻造形状较简单的单件、小批生产的锻件。自由锻设备有空气锤、蒸汽-空气锤和水压机等，分别适合小、中和大型锻件的生产。

Free forging has many advantages such as low productivity, large machining allowance, but simple tool and versatility. So it is widely used for forging single piece and ***all batch forgings with simpler shape. The free forging equipments include air hammer, steam air hammer and hydraulic press, etc., which are suitable for the production of ***all and medium he***y forgings, respectively.