No, not always. If during the design phase, the weld seam can be positioned outside any critical areas, the use of non-annealed tube is even recommended. Good deformable steel grades are available in both deep draw and high strength qualities. Annealing of tubes will add cost and logistic complexity to the supply chain. Furthermore, after annealing, the weld seam (the thinnest spot in the tube's circumference) will be the weakest spot.
Can the inside weld bead be removed to allow the bending over a mandrel or the fitting of the tube's ends over a closure?
A.
Yes, this is standard practice. The bead can be removed with a rest height of maximum 0.2 mm. It is also possible to make a smooth inside bead removal.
The standard length is 6 metres, but fixing to customer specification is no problem. The tubes will be manufactured to multiple lengths, cut, deburred and washed, according to specification.
In principle every steel grade can be successfully applied in a hydroforming process depending on the requirements. In general, for ease of processing it can be stated that for comparable strengths, steel grades should be used which have a high elongation and a high n-value. For more specific information on this item please contact our experts.
Yes. As a standard, Corus produces tubes from hot dip galvanised steel. Since the outside weld bead is removed a small unprotected area will remain. Upon request this can be post coated. After the removal of the inside bead, post coating is not possible. It is also possible to apply electrolitically zinc-coated steels, aluminised steels and even aluminium clad steels.
Will bending or any other preforming process influence the tube's hydroform capability?
A.
Yes, each process will use up part of the material's capability to deform. Although the hydroform process enables relatively large deformations, all materials have their limits (FLC's). Corus can help you select the right material with help of its material databank in combination with dedicated hydroform design software.
What tube sizes can be supplied for hydroform applications?
A.
Standard tube diameters are available within the range of 9.5 to 135 mm. Wall thicknesses can be supplied from 0.8 to 4.0 mm depending on diameter. Furthermore it is possible to supply to customer specific dimensions in rounds and other shapes. Please contact our experts if there are specific requests.
What tube sizes can be supplied for hydroform applications?
A.
Standard tube diameters are available within the range of 9.5 to 135 mm. Wall thicknesses can be supplied from 0.8 to 4.0 mm depending on diameter. Furthermore it is possible to supply to customer specific dimensions in rounds and other shapes. Please contact our experts if there are specific requests.
Will the tube's corrosive protection be compatible with the hydroform emulsion?
A.
Only approved emulsion and protection fluids are used from the major European suppliers. These are compatible with most post process application requirements. Data can be forwarded upon request.
As a standard all production runs are checked on a continuous basis with eddy current. Furthermore frequent samples are taken to perform flare and flattening tests and to check edge alignment. Upon request specific tests like the burst test can be made available (but not without prior investment).
In standard production it is possible to trace applied steel coils and heats per order. On customer request, tracebility can be extended to be per bundle (but not without great effort).
