Bending the tubes is an imminent step in several fabrication and manufacturing projects related to multifarious industries, from aerospace to household. So, every manufacturer needs to meticulously plan the process and other pre-requisites, from gathering and assembling the correct set of tooling to planning every step for ultimate success and optimal efficiency. But what matters the most in every tube bending operation is the choice of the correct material. Since there are several types of tube bending tooling, you cannot simply choose the workpiece material randomly.
It might lead to undesirable consequences that are hard to reverse. So, you need to understand the selection process of the correct material before proceeding with the execution of the tube bending operation. In this article, not only will we discuss the significance of material choosing but also shed light on the correct material options according to different tube bending tooling types.
Why material selection is crucial for tube bending?
Often manufacturers overlook the significance of selecting the right material for the tube bending operations. As a result, they end up with higher extent of material damage, improper bends, and reduced efficiency. The production cycle is also delayed and project completion cannot be executed within the deadline. Owing to this, everyone should be aware of the importance of selecting the right set of materials based on specific tube bending operation pre-requisites.
- Different materials possess a specific set of physical and mechanical properties, like hardness, mechanical strength, elasticity, and so on. If the right material is not chosen, it will become quite difficult to determine the variables needed for tube bending operations, like the bending pressure, bending dies, and many more.
- Also, if the proper material is not chosen, it will become increasingly difficult to achieve the desired bend radii without causing any structural deformity. For instance, stainless steel can easily withstand high amount of bending pressure and form a tight radii without any fracture or crack. On the other hand, mild steel won’t be able to withstand such a high pressure, not at least without structural deformation.
- Manufacturers need to keep on the mind that springback action is common for tube bending. Materials often try to regain their original straight shape after bending due to the cohesive force between the molecules. Therefore, choosing the right material will help manufacturers reduce the springback action and ensure the workpiece retains its bend structure without any structural deformation and fracture.
- Another reason to pay attention to the material choice is the surface finish. If the right material is not chosen, the workpiece might end up having surface defects, like cracks, wrinkles, and so on. Therefore, manufacturers should select the right material based on the bending tooling set and the physical and mechanical operational parameters.
- Cost efficiency can only be achieved if the right material is chosen for the tube bending operations. For instance, if you invest in hydroform bending but choose Inconel, you might end up with damaged workpiece or inaccurate bends. This will not only lead to material waste and delayed production but also incur huge operational costs.
What materials are best for different tube bending techniques?
The three most common forms of tube bending operations often implemented are hydroform, CNC, and bellows. So, understanding the right set of materials for each type of tube bending form is crucial.
Hydroform tube bending
In this technique, hydraulic pressure is implemented to create complicated bending structures along the workpiece. It ensures the structural integrity of the workpiece is not compromised by any means. Since the pressure exerted is quite high, it would be best to choose materials that are mechanically strong and can retain their structures with ease.
Stainless steel:
The ductile nature of stainless steel along with its exceptional mechanical strength make it suitable for hydroform tube bending process. Hence, its structural integrity will never be compromised, regardless of the variations in the input pressure.
Titanium:
This material is not often selected in the manufacturing industry owing to the high price. However, its features like corrosion resistance, higher strength-to-weight ratio, and temperature resistance make it the best option for applications requiring exceptional durability and strength.
Aluminum:
Thanks to its lightweight nature, improved formability, and enhanced thermal conductivity, it forms a better choice for hydroform tube bending operation. These qualities make the material best-suited for applications where temperature variations are abrupt and need to be handled appropriately.
CNC tube bending
In CNC tube bending, the operations are controlled through a set of instruction guides produced by a highly advanced computer program. Hence, it allows operators to achieve higher accuracy and precision in the bends to be created along the workpiece. Since CNC bending requires meticulous planning and can be applied to multifarious cases, the following are a few materials suitable for the same.
Chromoly steel:
Considered as a steel alloy with chromium and molybdenum, this material possesses qualities like increased toughness and exceptional physical and mechanical strength. Its higher ductility allows the CNC benders to create complicated and intricate bends with higher efficiency and accuracy.
Mild steel:
This specific version of steel is known for enhanced mechanical strength, higher ductility, and weldability. It also resists corrosion excellently, ensuring the surface finish is not compromised during the CNC tube bending operations.
Bellows tube bending
In bellows tube bending, an accordion-shaped structure is formed along the bending structure of the workpiece for higher stretchability and expandability. HVAC systems, automotive exhausts, and high-scale industrial machinery units often require bent tubes with the bellows for repeated expansion and contraction operations. Following are some of the materials usually used in this process.
Inconel:
Made with a combination of chromium and nickel, this superalloy is best-suited for physical operations requiring higher mechanical strength, hardness, and toughness. Since it is difficult to create the accordion structure using traditional tube bending techniques in Inconel, bellows tube bending seems to be the most reliable option.
Stainless steel:
Thanks to the exceptional mechanical strength and higher ductility, stainless steel is also a good choice for bellows tube bending operations.
Conclusion
Now that we have discussed the major materials used for different tube bending operations, it’s time you get started with the material selection based on the specific project requirements. Also, ensure to get your hands over the appropriate set of tooling to ensure higher productivity and efficiency.