Tube Forming Rolls
The process of forming sheet metal into tube shapes requires good sliding properties to guarantee forward movement of the strip and to facilitate shaping movement. In addition, the forming rolls must also be robust enough to withstand welding operations such as high-frequency induction (HFI) and laser welding.
Teaching an old mill new tricks can be a recipe for disaster if the material being run is not within the design latitude of the roll tooling and mill.
Forming rolls
When manufacturing welded metal shapes, roll forming can eliminate secondary operations. This type of forming provides superior structural strength and integrity, which can save both steel and construction labor costs. It can also produce parts with complex geometries that cannot be produced by extrusion. Nevertheless, the process can be challenging. It is important to consider the size, shape and physical properties of the product when designing a tube roll forming system.
Forming rolls are designed to orient the flat metal strip during the welding process. These specialized rolls ensure proper alignment and fusion between the metal tube forming rolls ends of the strip. They are made from a durable material, such as aluminum bronze, to resist wear and tear during the forming process. The material’s sliding properties and high hardness provide resistance against friction and stress, extending the life of the forming rolls.
The number of forming passes required for a given section varies by the geometry of the part, which can affect the overall process and the tooling costs. Additional forming passes help work out the “material memory” that results from previous bending. However, a higher number of pass can add stress to the product and lead to uneven tolerances.
A key aspect of the forming process is determining the most appropriate breakdown forming style and fin pass design for each section. For example, for lower yield materials with forming angles of 120-degrees and an inside bend radius of 1t-5t, a “k” factor of 3.5-40% is typically used.
Welding rolls
A welding turning roll is used to rotate cylindrical workpieces during seam welding. This is a key component in automating the welding process. In addition, it helps eliminate the need for manual manipulation of heavy workpieces. It can also reduce the need for rework or waste of material. This type of equipment is available in both powered and idler types and is used for a wide range of sizes.
Seam welding is a metalworking process that uses arc welding to join the edges of unfinished cylindrical workpieces. It is a fast, efficient method of production, and it produces custom metal components with a high level of accuracy and control. It also allows for in-line processing services like notching, punching, and welding to streamline operations and increase productivity.
When integrating GTAW or PAW with roll forming systems, it is important to ensure that the welding torch is properly positioned on the workpiece. This will enable the use of high-productivity welding parameters, as well as minimize the adverse effects of gravity. This is not always feasible with a manual system, so many manufacturers turn to welding positioners or rolling stands to help with this process.
These devices are designed to help take the burden off human workers, which can make them less likely to make errors. By taking over the repetitive and often tedious tasks, they can focus more on delivering quality outputs. In addition, they can be more productive since they do not have to stop to lift and manipulate hefty workpieces between processes.
Sizing rolls
The process of forming a flat piece of metal sheet into closed tubular sections requires careful engineering and precision in the manufacturing process. This is especially true for tube roll forming, which combines a series of precision-contoured forming rolls with welding and inspection rolls to create the desired metal strip product.
To help ensure proper metal flow during the forming process, sizing rolls are used to set the required progression of forming contours for each mill stand configuration and intended use. Specialized software dynamically applies these forming contours to the actual metal contour as it is being bent, allowing for precise control of the forming and welding processes.
For a successful tube and pipe production line, it is important to understand how varying steel wall thicknesses and yield strengths behave during the forming and welding processes. In addition, it is important to keep in mind that the shape of the resulting product will have an impact on the springback of the material.
In general, higher yield strength steels have lower elongation and are better suited for producing straight parts by rolling. However, the exact forming and welding parameters of a particular steel will depend on several other factors, including the number of pass cuts, mill condition and the overall complexity of the shaped product. For this reason, it is important to consider all of the variables when designing a sizing roll for your tube mill.
Inspection rolls
Rolls used for forming, welding, and sizing must be inspected regularly to ensure that they are free from defects. These inspections can be conducted by a professional with knowledge of quality control techniques and non-destructive testing (NDT). They may also use tools like microscopes or automated machines to detect flaws and defects in the rolls. They can also manage data in computer systems and ensure compliance with company and HSE procedures.
An eddy current inspection system is an excellent solution for inspecting the surface of hot rolling mills’ metal rolls. This technology reliably locates cracks near the surface that cannot be detected by human eyes. It also offers a variety of measurement functions that can be customized to meet the requirements of different applications.
Alternatively, an ultrasonic inspection system is a good choice for detecting defects in rolls. This technology works by transmitting a compression wave through the roll and analyzing the resulting echo. The resulting data is roll forming line then processed to determine the condition of the roll. In addition to detecting defects in the outer layer of the roll, this technology can also detect sub-surface defects.
Injection mold makers, aerospace machinists and tool designers often use this technique to inspect angles on their workpieces. It is a convenient and time-saving method for checking a number of dimensions, including core pin details, slide angles, and lock blocks.
