焊接专业英语翻译
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1.Pattern Material
Wood is the most common material for patterns. It is easy to work and readily available. Properly selected and
kiln-dried mahogany, walnut, white pine, and sugar pine are often used. Sugar pine is most often used because it
is easily worked and is generally free from warping and
cracking. Moisture in the wood should be about 5 to 6% to avoid warping, shrinking, or expanding of the finished
pattern. Metal patterns may be loose or mounted. If usage warra
nts a metal pattern, then the pattern probably should be
mounted on a plate and include the gating system. Metal is used when a large number of castings are desired from a
pattern or when conditions are too severe for wooden patterns. Metal patterns wear well. Another advantage of a metal
pattern is freedom from warping in storage. Commonly a
metal pattern is itself cast from a master pattern and can be replaced readily if damaged or worn.
Patterns are made of plaster and plastics. Plaster patterns are easy to make; they can be cast where origi
nal molds are available. However, plaster is brittle and
not suitable for molding large numbers of sand castings.
Plastics serve in several ways for pattern making. Some
conventional patterns are made of abrasion-resistant plastics with cost and durability between wood and metal. Anoth
er use of certain plastics is to make emergency patterns quickly or to salvage worn or broken patterns.
1.模型材料 木板是常用的材料，很容易去做并且很通用，普通的选择是
桃花芯木，胡桃木，白松和糖松。糖松是最常用的，很容易去制作而且很容易收缩和开裂很自如。在完成的模型中水分应控制
在5%-6%之间为防止变形、收缩、膨胀。
金属模型可能是实体的或模板的，模型可能被铸造在一个金属板上，包括浇注系统。当大量的铸件都特别需要一个模型
，或者条件非常严格时，就要用金属，金属模板的耐磨性很好。另一个优点是它不受储藏变形的限制。一般来说，金属模板
由一个主要模板铸造而成，如果它被损坏或磨损了也很容易被
替代。 模板由石膏和塑料制成。石膏模板很容易制作，它们可以
被制作当原始铸型，然而，石膏是容易损坏的，并且不适合于数量多的砂型铸造，塑料在模板制作中可以有很多方式，一般
现用的模板都由持久磨损的塑料和介于木头和金属之间的耐磨
材料制成。塑料的另一种用途是能快速做成应急模板或者用旧
的或者破损的模板。 2.Cleaning , Finishing Castings
After solidification and removal from the molds, most castings require some cleaning and finishing. These may
involve all or several of the following steps:
1. Removing cores. 2. Removing gates and risers.
3. Removing fins and rough spots from the surface. 4. Cleaning the surface.
5. Repairing any defects.
The required operations are not always done in the same order, and the particular casting process may eliminate
some of them. Because cleaning and finishing operations may involve considerable expense, some consideration shoul
d be given to them in designing castings and in selecting
the casting method to be used. Often substantial savings can be effected. In recent years much attention has been
given to mechanizing these operations. Sand cores usually can be removed by shaking. Somet
imes they must be removed by dissolving the core binder.
On small castings, gates and risers can often be knocked
off. However, on large castings, and often on small casti
ngs, they must be cut off, On nonferrous and cast iron castings this usually is done by means of an abrasive cutoff
wheel, power hacksaw or bandsaw. Gates and risers on steel castings, especially large ones, are often removed by an
oxyacetylene torch.
After the gates and risers are removed, small castings are often put through tumbling barrels, to remove fins,
snags, and sand that adhere to the surface. Tumbling also may be used to remove cores and, in some cases, gates and
risers. Frequently, some type of shot or slug material is
added to the barrel to aid in the cleaning. Larger castings may be passed through a cleaning chamber on a conve
yor, wherein they are subjected to blasts of abrasive or cleaning material. Large castings usually have to be finis
hed manually, using pneumatic chisels, portable grinders,
and manually directed blast hoses in separate cleaning rooms.
Although it is desirable that casting contain no defects, it is inevitable that some will occur, particularly in
large castings where only one or a few of a particular
design are made. Some types of defects can be repaired
readily and satisfactorily by arc welding. However it is
imperative that the casting be of a material that can be welded satisfactorily, that all defective areas be remov
ed down to sound metal by grinding, or chipping, and that a sound repair weld be made.
2.清洗，整理铸件 凝固后、清除模具，大多数铸件需要一些清洁和整理活动。
这些可能涉及所有或几个下列步骤。 1.移除内核。
