Casting VS Forging
There are several different methods and techniques in manufacturing metal components. Some use castings and other use forgings.What is casting or forging? What are the differences between casting and forging? Based on the purpose and end use of the metal part, different procedures are used to create the highest quality piece possible. This is the best choice! But what will be more effective for their metal component and most cost effective? To find out the differences between casting and forging. You will know which one is better for your business.It will improve the excellence of your product. If you want to get a reliable and durable,Learning this article.It is very useful.
What is casting?
Casting is the process where metal is heated until molten. Then pouring or injecting molten metal into a mold vessel to create a desired shape. If the shape of the component is a very large size,casting process is beneficial. Because it use mold,it is easy to get a net shape or similary net shape parts.Sometimes the machining costs can be saved. Once the metal cools into the basic desired shape, to get more precision casting,we can me post treatment. The metalworker then finishes the part with the details requested by the client either by hand or through further machining.
Metal casting processes can be classified either by the type of mold or by the pressure used to fill the mold with liquid metal.Casting can be perfected to higher quality producing material with greater strength and we arability depending on the correct selection of alloys, and heating them to their greatest temperatures.
Fundamentals of Casting Casting is a solidification process. Therefore, the microstructure can be finely tuned, such as grain structure, phase transformations and precipitation. However, defects such as shrinkage porosity, cracks and segregation are also intimately linked to solidification. These defects can lead to lower mechanical properties. A subsequent heat treatment is often required to reduce residual stresses and optimize mechanical properties.
Advantages of Casting?
|Melting of metal allows it to be formed into greater variety of shapes, which allows for greater flexibility in part design|
|Cast parts are nearly always lighter than their forging counterparts|
|Initial results are often closer to design specifications, lessening time spent on secondary machining and processing|
|Smaller production “runs” required|
|For large and complex components – casting is a fantastic method of manufacture|
|Complicated/complex parts are no problem|
|Tooling is often less expensive than forge dies|
|No real upper size limit in casting weight|
|Large range of alloy choices , alloys including Chrome, Nickel and Moly can be added at the molten stage.|
For large, complicated, intricate or otherwise unsuitable for the forging process wear parts and components, we can use castings
What is Forging?
Forging is a metal forming processes. This process does not involve heating.It is the application of thermal and mechanical energy to steel billets or ingots,then hammered and manipulated into the final desired shape.Forgings are generally stronger than castings.But for forging Components can not be very complex.Because there are some limitations to manufacturing capabilities of forging. Usually if a component needs to be forged and also needs to meet certain size requirements, the component needs to be machined after it has been produced.Forging can be performed under different temperatures:cold, warm and hot, depending on the material. The process of forging is preferred where a component requires higher strength.
Forging results in metallurgical crystallization and grain refinement as a result of the thermal cycle and deformation process. This strengthens the resulting steel product particularly in terms of impact and shear strength.Forged steel is generally stronger and more reliable than castings and plate steel due to the fact that the grain flows of the steel are altered, conforming to the shape of the part.
Advantages of Forging?
|superior structural integrity and mechanical strength|
|save cost than casting thanks to less intensive labor requirements and less involvement of material scrap|
|eliminates surface porosity along with voids and other defects|
|The nature of forging excludes the occurence of porosity, shrinkage, cavities and cold pour issues|
|Will handle impact better than castings|
|Forging is more consistent in the yield of produced parts and in producing parts that are incredibly strong and ductile|
|The tight grain structure of forgings making it mechanically strong. There is less need for expensive alloys to attain high strength components.|
|The tight grain structure offers great wear resistance|
Types of Forging
|Open Die Forging|| Open die forging is one of the oldest forms of manufacturing, using traditional blacksmith methods. The billet is heated above recrystallization temperature, ranging from 1000°C to 1300°C for steel, and gradually shaped by skilful hammering or pressing of the work piece to create the desired shape. Open die forgings produce strong, durable parts in sizes that range from a few pounds to hundreds of tons. As a result, it is a favorable method to produce large and simple parts such as bars, rings, blanks, hollows, and spindles. Open die forging is also a great open for custom metal components as well.|
|Closed Die Forging||Closed die forging is the process where a pressing of forging stock is accurately and uniformly shaped into a die, or set of top and bottom dies, depending on the design requirements. The alloy deformation is confined within the shaped cavity of the dies to achieve the desired engineering configuration. Depending on such factors as complex multi-segmented precision wrap dies to simple two-piece conventional top-and-bottom dies. Process by which the material is placed between two dies with upper & lower impressions designed for the desired shape of the forging. Conventional forgings are produced through the use of a single pair of die or with multiple impression dies.|
Difference between Forging and Casting
For casting and forging,each process has its own advantages.one method is preferred for certain projects while the other is better suited to others. Below we list out the main differences between casting and forging:
1: Strength Difference:
Casted material is low in strength as they are poured into a cavity which lets the material take its shape freely.
Forged material are stronger as they possess a definite grain structure which is pressed with force, increasing their mechanical strength.
2: Suitability for Hollow Shapes
Casting is often preferred for the production of material containing hollows spaces or cavities.
Forging excludes cavities and porosity from their compositions.
3: Uniformity Different:
The casted material is not always uniform.
Forged material can be made to a uniform structure preserving consistency in shape.
4: Size Restrictions:
Casting doesn’t have any size or shape limitations as all material will be melted before putting them into shape.Materials weighing up to 50kgs can be forged yet higher power is required if material to be forged is heavier than 50kgs. In this case, casting would be the alternative.
5: Level of Complexity
Casting is able to produce complex patterns and shapes. Forging is more focused in producing uniform and simple material.
6: Cost Different:
Casting uses relatively inexpensive equipment.Machines used for forging such as heavy duty industrial dies are more expensive.
Here is a research paper, researchers at the University of Toledo compared the differences between one type of product made both ways. the following conclusions were drawn:
• The tensile strength of forged parts is 26% higher than that of cast parts.
• The fatigue strength of forged parts is 37% higher than that of cast parts.
• Cast iron exhibits only 66% of the yield strength of forged steel.
• Forged parts exhibit a 58% reduction in area when pulled to failure, while cast parts exhibit a 6% reduction in area.
Via this article, you can understand the differences well. When you decide the parts choosing,that will be useful!