通過(guò)鍛造能消除金屬在冶煉過(guò)程中產(chǎn)生的鑄態(tài)疏松等缺陷，優(yōu)化微觀組織結(jié)構(gòu)，同時(shí)由于保存了完整的金屬流線，鍛件的機(jī)械性能一般優(yōu)于同樣材料的鑄件。

Forging can eliminate the defects such as casting porosity and so on during the smelting process, and optimize the microstructure. At the same time, because of the intact metal flow line, the mechanical properties of the forgings are generally better than those of the same materials.

自由鍛都是以生產(chǎn)批量不大的鍛件為主，采用鍛錘、液壓機(jī)等鍛造設(shè)備對(duì)坯料進(jìn)行成形加工，獲得合格鍛件。 自由鍛的基本工序包括鐓粗、拔長(zhǎng)、沖孔、切割、彎曲、扭轉(zhuǎn)、錯(cuò)移及鍛接等。自由鍛采取的都是熱鍛方式。

Free forging is in the production of small quantities of forgings, the forging, hydraulic press forging equipment is carried out on the blank forming process, obtain qualified forgings. The basic process of free forging including upsetting, stretching, punching, cutting, bending, torsion, displacement and welding etc.. The free forging is all hot forging.

在鍛造時(shí)，金屬的脆性雜質(zhì)被打碎 ，順著金屬主要伸長(zhǎng)方向呈碎粒狀或鏈狀分布；塑性雜質(zhì)隨著金屬變形沿主要伸長(zhǎng)方向呈帶狀分布 ， 這樣熱鍛后的金屬組織就具有一定的方向性。

When forging, the brittle metal impurities to be broken down, the main direction of elongation is like particles of metal or plastic chain distribution; impurities with metal deformation distributed along the main direction of elongation, so after hot forging metal organization has certain direction.

低塑性拔長(zhǎng)時(shí)，應(yīng)注意選擇合適的送進(jìn)比，送進(jìn)比太小時(shí)，變形集中在上下部，中心都鍛不透，并沿軸向產(chǎn)生拉鍛造應(yīng)關(guān)于鍛件的一些基本知識(shí)力，導(dǎo)致內(nèi)部橫向裂紋產(chǎn)生。在鐓粗時(shí)，常用軟襯墊鐓粗或疊鐓（用于鍛薄餅形零件），以改善變形的不均勻性，防止產(chǎn)生表面裂紋。選擇好的鍛件產(chǎn)品跟鍛造工藝或者鍛造廠家肯定是有關(guān)系的，現(xiàn)在有越來(lái)越多的鍛件廠走向市場(chǎng)，對(duì)此，用戶(hù)挑選鍛件產(chǎn)品的難度就增加了。

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.