低塑性拔长时，应注意选择合适的送进比，送进比太小时，变形集中在上下部，中心都锻不透，并沿轴向产生拉锻造应关于锻件的一些基本知识力，导致内部横向裂纹产生。在镦粗时，常用软衬垫镦粗或叠镦（用于锻薄饼形零件），以改善变形的不均匀性，防止产生表面裂纹。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。

When low plasticity is pulled out, attention should be paid to selecting suitable delivery ratio, sending too much time, deformation on the upper and lower parts, and the center can not be built, and forging along the axial direction should be related to some basic knowledge of forging, resulting in the occurrence of internal transverse cracks. In the upsetting, commonly used soft liner (for upsetting or folding upsetting forging thin pancake, uneven parts) to improve the deformation, prevent the generation of cracks on the surface.

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.

由于热变形形成纤维***，会使金属的力学性能出现异向性，即纵向力学性能指标中的A，Z，Ak比横向相应的指标大得多，两个方向上的强度Rm。Re差别不大。

Due to the formation of fibrous microstructure by thermal deformation, the mechanical properties of metals will be different. That is, A, Z and Ak in longitudinal mechanical properties are much larger than those itransverse direction, and the strength in two directi is Rm. Re is not very different.

拔长 拔长是使坯料的长度增加，截面减小的锻造工序，通常用来生产轴类件毛坯，如车床主轴、连杆等。

冲孔 用冲子在坯料上冲出通孔或不通孔的锻造工序。弯曲 使坯料弯曲成一定角度或形状的锻造工序。

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.