While metal casting might be the best process to manufacture a wide range of components, depending on your needs, the forging process could be the best option. Or vice-versa. This is why it helps to know the key differences between forging and casting. So here are 5 things to consider when deciding if a casting or forging is right for your component, application, and overall needs.
RUNCHI Product Page
1. Size of the Finished Product
One of the more notable differences between metal castings and forgings is the maximum size of a finished product. The process of forging moves metal while it is still in a solid-state. This requires a tremendous amount of force to modify the original shape of the metal and the force needed drastically increases as the size of the section gets larger. Since castings start out as liquid molten metal, it can flow into nearly any shape or size if there is a mold that matches.
Another consideration pertains to the weight of the parts. If there are two identical parts, one made by casting and one by forging, the casting will usually be lighter than the forging. As a result, conversions from forgings to castings typically result in a weight reduction.
2. Design of the Component
When it comes to designing a part for either a casting or forging, some characteristics to evaluate include:
- Part complexity
- Tolerances
- Grain structure
- Structure integrity
When assessing the complexity of a part, forgings can be limited. Small details and internal cavities are sometimes difficult, if not impossible, to shape in the forging process.
Alternatively, the beginning liquid nature of a casting creates a distinct advantage for complex shapes in that it can easily flow into small, detailed areas. Part of this benefit also comes from the reduced machining required after casting because of the details that are present in the original casting.
In the design and prototype phase of a program, castings are more cost and time-efficient. Changing a small detail in the casting pattern of a component is much easier than a forging die.
3. Alloy Selection
A prominent difference when it comes to castings vs forgings is the availability of alloys to use. In forging, the components are made from billets produced at a steel mill. These mills generally only manufacture a specific number of grades and alloys.
In comparison, castings are melted and poured at the foundry making special alloy costs more manageable. When choosing alloys and a manufacturing process, an important consideration is the desired ferrite content. Ferrite, in controlled amounts, has characteristics that make it more corrosion resistant than a similar forging.
4.
I
nternal Strength of the Component
Another characteristic to consider relates to the internal structure and strength of the component. The forging process alters the grain structure and can &#;aim&#; or &#;point&#; it in a particular direction creating a directionally strong component. Forged parts are anisotropic (contains different property-measurement values in different directions) while castings are isotropic (contains similar property-measurement values in all directions).
Deciding between the two processes depends on the application it will be used for; forgings will typically be stronger in a particular direction, but castings are stronger uniformly throughout.
When the application involves frequent impacts, a forging will retain its shape longer, if a uniformly strong component is needed for the application, a casting will perform better.
5. Cost of Castings vs. Forgings
The price of castings vs. forgings depends on multiple variables, each of the processes are less expensive in some cases and more expensive in others. Various factors that play into the price of a part are:
- Production volume
- Alloy
- Shape complexity
- Specific process of casting or forging
- Specifications including required testing
Forgings are most cost effective for medium to large lot sizes. Castings can be effectively purchased in small, medium, and large lot sizes.
Raw material costs for castings are generally lower than forging since the initial process of casting ingots and processing them into billets is eliminated.
Tooling for most centrifugal castings and open die forgings (ODF) is not required. For closed die forgings (CDF) tooling can be expensive. For high volume applications, purchasing dedicated tooling is a good idea for all processes as it will reduce the per-piece cost.
It is a good idea to buy castings machined since the foundry can cost effectively recycle machining chips through re-melting. Since that benefit doesn&#;t exist for forgings, it&#;s best to buy them in the as-forged condition. Machining rates for castings are comparable to forging for most alloys. However, due to finer grains in forgings, some nickel-based alloys and stainless steels have better machinability.
Since the cost comparison of metal castings vs. forgings depends on many variables, you should have discussions with leading companies in the casting and forging industry to discuss your specific project and obtain quotes for both processes.
Advantages of Metal Casting Process
- Metal castings have an extremely high upper size limit in casting weight (if none).
- Large range of alloy choices.
- Tooling costs in the metal casting process are often less expensive than forging dies.
- For forgings, custom alloys are more difficult to produce whereas with casting, alloys including nickel, chrome, and moly can be added at the melting stage.
- Smaller production runs are not a problem.
- Extremely adaptable to mass production needs.
- Complex parts and/or thin walled parts are typically not a problem.
- Liquid metal can be formed into variety of shapes, allowing greater flexibility in part design.
- Modifications of part designs and molds are easier and quicker to implement.
- Post-casting results are close to design specifications, reducing time spent on secondary processing/operations.
- Cast parts are typically lighter than forgings.
- Lead times can be shorter, especially in the case of centrifugal castings.
Advantages of Metal Forging Process
- Metal Forgings generally, have higher mechanical properties and better ductility (depending on alloy).
- Will typically handle impact better than castings.
- Continuous grain flow and finer grain size.
- Forging metal usually eliminates the occurrence of porosity, shrinkage, cavities, and cold pour issues.
- Greater wear resistance due to grain flow.
- In some cases, metal forgings can be cheaper than castings.
Summary
In the world of manufacturing metal components, there is no &#;one size fits all&#;. Depending on your specific metal component, its application, and your overall needs, either a casting or forging could be the best fit. You may have some metal requirements for which casting is the best fit but forging for others. Ultimately, the best way to determine which process is best for your specific requirements is to consult with the manufacturers.
Want more information on Block forging? Feel free to contact us.
If you think metal casting might be a fit for your application, give us a call or submit a request for quote.
Forging vs. Casting
Forging and casting are two popular methods used to manufacture products. While both methods have their own advantages and disadvantages, there are several benefits of forged products over casted products. Here are some points to consider:
- Strength: Forged products are stronger than cast products due to the process of shaping metal under high pressure, which improves its grain flow structure and makes it denser. This makes forged products more durable and long-lasting than casted parts.
- Material properties: Forged products have better material properties compared to casted products. The forging process aligns the grain structure of the metal, which enhances its mechanical properties, such as toughness, ductility, and fatigue strength.
The Science Behind The Forging Process
Forging processes employ mechanical force to shape metal billets, such as rolling, pressing, hammering, or similar techniques, while they remain solid. This heating and deformation process refines the internal grain structure of the metal by allowing metallurgical recrystallization to occur. This results in a more uniform structure throughout the metal form, giving it greater strength and resistance to impact and shear damage.
The benefits of forging processes are numerous, making it a popular choice for shaping metal billets.
Forged metal parts are known for their high strength and durability, making them ideal for use in high-stress applications. The uniform grain structure that results from the forging process also makes the metal more resistant to fatigue and cracking, which can be critical in applications where failure is not an option.
Because the metal is shaped while it is still solid, forging can create parts with a high degree of accuracy and detail, which can be important in critical industries such as aerospace or medical device manufacturing.
There are a variety of forging techniques available, each with its own strengths and limitations. For example, rolling can be used to create long thin parts while hammering is better suited to creating complex shapes and profiles.
Finally, it's worth noting that forging processes can be more energy-efficient than other metal-shaping techniques, such as casting. Overall, the combination of energy efficiency, strength, and flexibility makes forging a highly attractive option for manufacturers who are looking to reduce their environmental impact while still producing high-quality parts.
It's also important to note that while forging produces stronger and more durable parts, it may not be suitable for creating highly complex shapes or intricate designs. In these cases, casting may be the better option.
Casting: An Effective Method for Producing Complex Parts
The process of metal casting involves pouring molten metal directly into an existing mold. The cast metal then cools and hardens into a solid state the exact shape of the mold. Manufacturers choose from various types of molds based on order size and part complexity.
Although metal casting has been used for centuries, it is now primarily used for parts that are too large or unwieldy for metal forging. Casting is an ideal method for creating intricate geometries that cannot be produced through the application of force alone.
Benefits of metal casting over forgings in certain scenarios, when it comes to creating metal parts, casting can be an excellent alternative to forgings, particularly because of the following benefits:
- Fewer Restrictions on Size and Complexity: Castings can be created for parts of virtually any size or complexity level, making it a versatile option.
- Greater Range of Metal Options: A wider range of specialty alloys can be used in castings since chrome, nickel, and molybdenum can be more easily incorporated into the molten metals.
- Cost-Effective for Low-Volume Production: Castings are ideal for producing small production runs more cost-effectively, particularly since the tooling is cheaper than the equivalent forging dies.
Ultimately, the decision between forging and casting comes down to a variety of factors, including the specific requirements of the project, the available budget, and the desired end result.
By carefully considering all of these factors, you can choose the best production method for your project and ensure high-quality, reliable results.
Overall, while casting may be a more cost-effective option for certain products, forging offers unique benefits in terms of strength and material properties that cannot be obtained in any other way. Forged parts are superior and are preferred in critical application areas where the parts must perform at the highest level.
For more information on our forging capabilities contact us.
The company is the world’s best Custom Universal Joints supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.