Notes

[1] Metal flow and grain structure can be controlled, so forged parts have good strength and toughness, they can be used reliably for highly stressed and critical applications. Forging may be done at room temperature (cold forging) or at elevated temperatures (warm or hot forging).

句意：由于锻造可以对金属的流动和晶粒结构进行控制，因此锻件具有很好的强度和韧性，能可靠地用于承受较大应力和要求严格的工作环境。锻造可以在室温（冷锻）或高温（温锻或热锻）C下进行。

[2] The open-die forging process can be depicted by a solid workpiece placed between two flat dies and reduced in height by compressing it. This process is also called upsetting or flat-die forging.

句意：自由锻的操作过程是将工件放在两个平模之间，在压力作用下减小其厚度，故又称为墩粗或平模锻。

[3] The flash has a significant role in the flow of material in impression-die forging. The thin flash cools rapidly, and because of its frictional resistance, it subjects the material in the die cavity to high pressures, thereby encouraging the filling of the die cavity.

句意：锻件的飞边对金属材料在模锻过程中的流动有重要的影响。飞边较薄，冷却较快，造成摩擦阻力，使模腔中的金属材料由于无法继续向外流动而受到很高的压力，有利于它在模腔中的充填。

[4] Preforming processes, such as fullering and edging (Figs. 4.2 b and c), are used to distribute the material into various regions of the blank, much as in shaping dough to make pastry. In fullering, material is distributed away from an area; in edging, it is gathered in to a localized area.

句意：（锻件毛坯的）预成形如压肩和卡压（见图4.2b, c）是对毛坯材料在不同区域进行分配，如我们在制作糕点时首先要将面团揉捏成初始的形状一样。卡压是使坯料从某处向两端分配，而压肩则是使坯料集中在某个局部区域。

[5] Coining essentially is a closed-die forging process typically used in minting coins, medallions, and jewelry; the slug is coined in a completely closed die cavity.

句意：精压是一种典型的闭式模锻成形工艺，常用于硬币、徽章和首饰的制作；小片的金属坯料在完全闭合的模腔中成形。

[6] The grinding process, if not controlled properly, can cause surface damage from excessive heat and can induce harmful tensile residual stresses on the surface of the die, which will reduce its fatigue life.

句意：对于磨削，如果操作不当会因为过热造成模具表面损伤，在模具表面会产生有害的残余拉伸应力，从而降低其疲劳寿命。