专业材成英语3.doc

专业材成英语3.docSome of the metal forming processes are rolling , extrusion , drop forging , wire drawing , press forging ,sheet
metal operations , upset forging・一些金属成形过程是轧制、挤压、落锤锻造，拉 丝，按锻造、金属板操作、顶锻
These are secondary manufacturing processes where the starting raw materials are processed by any of the
previous manufacturing processes described .这些是二次制造过程的起始原料处 理前面的任何制造过程描述。It essentially, envolves joining pieces either permanently or temporarily so tha/t they would perform the necessary function. 它 从本质上讲,envolves加入碎片要么永久或暂时如此，他们将执行必要的功能。The joining can be achieved by either or both of heat and pressure and/or a joining ma/terial. 的加入可以达到的一种或两种热量和压力和/或加入材料。Many of the steel structural construetions we see are first rolled and then joined together by
a fabrication ,我们看到的是第一卷，然后连接在一起的工艺 过程。
Some of the processes of interest in this ca/tegory are gas welding, cold welding, electrie arc welding, brazing, electrie resistance welding, soldering, thermit welding.
一些感兴趣的过程都属于这一类气体焊接、冷焊接、电弧焊、钎焊、电阻焊、钎焊、铝 热焊。
These are also secondary manufacturing processes where the additional unwanted material is removed
in the form of chips from the blank material by a harder tool so as to obtain the final desired shape.
这些是二次制造工艺，额外的不必要的材料去除的形式的芯片从空白材料的困难，得到 了工具最终想要的形状。
Material removal is normally the most expensive manufacturing process because more energy is consumed
and also, a lot of wa