跪求机械制造专业英语翻译

发布网友发布时间：2022-05-06 01:51

共1个回答

热心网友时间：2022-06-28 11:59

There is much more to casting than selecting a process and making the appropriate pattern .During the past decade ,research and proction experiences have provided scientific principles for better casting techniques .Important considerations are the rate at which a mold cavity is filled ,gate placement ,riser design ,the use of chill blocks, and padding.
铸造并不仅仅是选择工艺流程和合适的模型。在过去十几年间，对铸造业的研究和生产经验的总结已经使得铸造工艺越来越科学。着重集中在型腔如何灌注，进模口的布置，冒口的设计，冷硬试件的使用，垫模这些方面。
FILLING THE MOLD CAVITY .the velocity with which the molten metal fills the mold is determined by the cross-sectional area of the gating system and the mold-pouring rate. Too slow a mold-pouring rate means solidification before filling some parts, allowing surface oxidation. Too high a pouring rate caused by too large a gating system causes sand inclusions by erosion ,particularly in green-sand molding ,and turbulence. The minimum cross section in the gating system is called a choke .In the strict sense, the choke is the section in the gating system where the cross-sectional area times the potential linear velocity is at a minimum. When the gate system is choked at the bottom of the sprue ,it is called a nonpressurized system. This system is somewhat less reliable than a pressurized system in which the choke is at the gate.
充型的过程，
金属液的充填速度其实是取决于浇注系统的横截面积和浇注速率的。浇注速度太慢的话会使得金属液到达某些部分之前出现凝固（冷隔？），而这又将导致表面氧化。由于浇筑口大而使浇注速度过快的话又会出现砂眼（尤其是湿砂造型的时候）和紊流。浇注系统中横截面积最小的那个被称为阻塞面（choke不知道是不是这样译），严格意义上来讲，阻塞面应当是液流线速度最小的那个面。如果浇注系统在浇注口的底部进行阻塞的话，这就是一个开放式浇注系统。这种系统的可靠性比那种阻塞面设置在浇口的增压铸造系统稍差。
The first metal in the pouring basin and down the sprue usually has some turbulence that carries slag into the runner .To avoid slag in the casting, the runner should extend past the last gate to trap the initial slag. By the time the gate become operative, the liquid level should be high enough so that no slag can enter the casting cavity .The runner should be laid out to minimize turbulence, that is it should be as straight and as smooth as possible. The gate that was shown in Fig.7-3 is made to enter the cavity at the parting line. Gating arrangements may also be made at the top or bottom of the cavity. The parting line gate is the easiest for the pattern maker to make; however, the metal drops into the cavity, which may cause some erosion of the sand and some turbulence of the metal .For nonferrous metals, this drop aggravates the dross and entraps air in the metal.
Top-gating is used for simple designs in gray iron, but not for nonferrous alloys, since excessive dross would be formed by the agitation.
Bottom-gating provides a smooth flow of metal into the mold. However ,if does have the disadvantage of an unfavorable temperature gradient. It cools as it rises, resulting in cold metal in the riser and hot metal at the gate.
浇池中的第一种金属浇入的时候通常都会产生一些带熔渣的紊流。为了避免这种熔渣，浇道必须延伸过浇口以*熔渣。当浇口处于工作时，液面必须具有足够的高度以防止熔渣进入型腔。浇道必须设置为尽量减少紊流的样式，亦即尽可能的直和平滑。图7-3中所示浇口即为从分型线进入型腔。浇口也可以设计在型腔的顶部或是底部。而分型线浇口则是最易于模具制造商制造的；尽管如此，金属液流入型腔的时候还是会带来砂子的侵蚀和紊流。对于有色金属，这种流入使得浮渣和带入空气的现象更严重了。顶注式浇筑系统用于一些简单的灰口铁浇注设计，并不适用于有色金属，因为过多的搅动会带来额外的浮渣。而底注式浇口虽然提供了一个平滑的液流，但是会产生温度梯度——这恰恰是我们不愿意见到的缺陷。当其不断上升的时候会冷却，导致冒口过冷，浇口过热。

时间仓促....见谅