在考慮鍛造工藝時特別是后一火的鍛造時，應盡量避免在臨界變形程度下進行，以免得到粗大晶粒組織。具體來說，高溫下金屬塑性好，變形抗力小，應采用遠大于臨界變形程度的較大變形量鍛造；低溫修正時采用低于臨界變形程度的小變形量進行局部修整。

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

鍛造是指把加熱后的金屬材料鍛制成各種形狀的工具、機械零件或毛坯。鍛造過程中要對這些滾燙的金屬坯料進行各種加工，因此加工過程中高溫、、振動和噪聲是避免不了的。所以鍛造過程安全防護很重要。

Forging is a tool, mechanical part, or blank that is forged from a heated metal material to a variety of shapes. In the process of forging, these hot metal billets should be processed, so high temperature, dust, vibration and noise can not be avoided during the process. Therefore, the safety protection of the forging process is very important.

拔長 拔長是使坯料的長度增加，截面減小的鍛造工序，通常用來生產(chǎn)軸類件毛坯，如車床主軸、連桿等。

沖孔 用沖子在坯料上沖出通孔或不通孔的鍛造工序。彎曲 使坯料彎曲成一定角度或形狀的鍛造工序。

Drawing and drawing is a forging process that increases the length of the billet and reduces the section. It is usually used to produce shaft parts, such as spindle and connecting rod.

Forging punch punching out through holes or blind holes in the blank. The forging process of bending the billet into a certain angle or shape.

自由鍛造是靠人工操作來控制鍛件的形狀和尺寸的，所以鍛件精度低，加工余量大，勞動強度大，生產(chǎn)率也不高，因此它主要應用于單件、小批量生產(chǎn)。

Free forging is by manual operation to the shape and size of the forgings, so the precision of the forgings is low, the processing allowance is large, the labor intensity is big, and the productivity is not high. Therefore, it is mainly used in single piece and small batch production.