Corus Hyfo offers automotive engineers the most convenient access ...

The ultimate blankfor a wider scope ofapplicationsThe Tubular Blank

InnovationIncrease of safety requirements, weight reduction,quality improvement, cost reduction... these are just afew of the vital issues the modern Automotive Industryis dealing with. Here, the key to successful rationalisationand optimisation lies in innovation.Pioneering workThe need for innovation is recognised and valued byCorus Hyfo. This cooperative body is Corus's newknowledge portal to advanced hydroforming technology.As such it can give significant support in the realisationof serious improvements in car architecture. Thiseffort is effective; Corus Hyfo achieved an importantbreakthrough which can be a valuable asset to theAutomotive Industry.THE Tubular BlankTogether with Soudronic, the leading company intailor-welded blank technology, Corus Hyfo developedTHE Tubular Blank; a new custom-made input formodern hydroforming processes. At the root ofTHE Tubular Blank's production process lie specificaspects: the use of blanks, possibly produced out ofthe width of a coil, a dedicated forming process, laserwelding and monitoring. Because of this innovativecombination, THE Tubular Blank can facilitate thehydroforming process and optimise its benefits.AvailabilityAs first of its kind in the world, THE Tubular Blank isnow commercially available. With the new compactand flexible production technology, Corus Hyfoeventually intends to deliver THE Tubular Blank fromoptimal located sites in the Western world.

Attributes ofa technologicalbreakthrough

THE Tubular BlankFacilitates the hydroformingprocess and optimisesits benefits.Extended D/t ratioConicalTailor-madeImproved formabilityExact to lengthBurr-freeGalvanisedZnZnZnA-class surfaceASteelStainless steelAluminium

What isnow provedwas onceonlyimaginedThe Tubular Blank

50 mm < D > 250 mm900 mm < length > 4000 mm0.60 mm < t > 3.00 mmt = thicknessD = diameterD/t ratio up to 250Thichness (mm)250200150100D/t ranges Tubes and THE Tubular BlankTHE Tubular Blank500.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0Diameter (mm)TubesTHE extended D/t ratioWhereas conventional tubes have amaximum D/t ratio (diameter/wallthickness) of 75, THE Tubular Blankcan reach a D/t ratio of up to 250,with dimensions meeting DIN 2394-1and a weld according to ISO 13919-1,quality B. This is possible because ofthe specific forming and laser-weldingprocesses. This latter process ensuresan optimal weld seam. The formingprocess guarantees the right mechanicalproperties and flexibility for the ensuingprocess of hydroforming.

Nowready totake off forhydroformingtechnologyTHE Tubular Blank: Tailored & ConicalBecause THE Tubular Blank's production process is blank-basedTHE Tubular Blank can be either cylindrical or conical. Wall thickness canbe varied along the blank (from 0.6 mm up to 3.0 mm). The tailor-madeblanks are fed into the forming station, resulting in Tailored TubularBlanks, with either longitudinal, radial or spiral welds. As far as ConicalTubular Blanks are concerned, the diameter of THE Tubular Blank canvary approximately 30% over a length of 1000 mm.

Tailor-made, thickness 0.60 mm < t > 3.00 mmWelds in longitudinaland radial direction(spiral direction optional)xx + 30%1000 mmTailored & Conical

The Tubular BlankWhenformabilityincreasescar architectureimproves

THE improved formabilityConventional tubes are roll formed;THE Tubular Blank is not. This isjust the difference that accountsfor the improved formability.As sheet material is formed into atube, this deformation results ina decrease of formability. Thisdecrease is greater with rollforming than it is with the formingprocess applied in the productionof THE Tubular Blank.Consequently, THE Tubular Blankhas more formability left for furtherforming processes such ashydroforming. Formability of thelaser-weld can reach values of95% of the base material. And ifTHE Tubular Blank is produced outof the width of the coil, formabilitywill even increase with 2.5 - 3%Max blow diameter (mm)250245240235230225Formability due to width of coilL1 L2 L3 L4 L5 L6 W1 W2Test specimenW3250245240235230225L = Tube from length of coilIF Rephos 220 formability referenceW = Tube from width of coilFormability due to forming processRp0.2 Roll-formed tubeRp0.2 THE Tubular BlankRp0.2 BlankEngineering stress (Mpa)Ag Roll-formed tube= 88%Engineering strain (%)Ag THE Tubular Blank= 94%Ag Blank= 100%

When lessis neededmoreThe Tubular Blank

Exact to length& Burr-freeAA-class surfaceZnZnZnGalvanisedMulti metalExact to length and burr-freeThe great advantage of using accurately cutblanks is that THE Tubular Blank can beproduced to exact length. Cutting is no longernecessary and accuracy is in line with normalblank requirements. The input of blanks and theabsence of cutting also assure that THE TubularBlank is absolutely burr-free.Galvanised Tubular BlanksTHE Tubular Blank can be produced out ofgalvanised materials. The welding processallows for galvanisation which has already beenproved with tailored blanks. The laser-weldseam has minimal width and guaranteesoptimal corrosion resistance.A-class surfaceThe forming process allows THE Tubular Blankto retain A-class surface quality.This is a great advantage compared to conventionalroll-formed tubes.Multi metalTHE Tubular Blank's production process offersa unique possibility of using different materials.Steel, stainless steel, aluminium: the productionunit can process all three of them. In case ofaluminium, bi-focus laser welding technologywill be applied.

The Tubular BlankThe developmentwas oursthe benefits areyours

The application of hydroformedcomponents such as the hollow sectionsof the Body in White (BIW) require thinwalled Tubular Blanks with a D/t ratio ofup to 150. Compared to conventional tubes,THE Tubular Blank can make a difference as itcan reach a D/t ratio of up to 250. This makesa wider scope of applications in the BIWpossible. Weight reduction and componentintegration are now within reach.Conical Tubular Blanks facilitate theforming process of sloping shapes.Consequently, a wider scope ofhydroforming applications can be realised.Tailored Tubular Blanks lead to weightreduction as they restrict the use ofmaterial to those areas where it isreally needed. In turn, such optimaluse of material can result in less componentsand thus cost reduction.Because of improved formabilityannealing is in many cases no longerneeded. Next to that the hydroformprocess stability will increase.Furthermore, parts can be dimensioned lighterand more components can be integrated.Being exact to length, THE TubularBlank fits the requirements formodern assembly technologies suchas laser welding better.ZnZnZnAs there is no need for extra cutting,consequently, THE Tubular Blank isburr-free, and is directly suitable forhydroforming. Pre-processing or cleaning is notnecessary. This, in turn, also results in lowercosts.As annealing can be avoided galvanisedmaterial can be used. Being producedout of galvanised blanks, THE Tubular Blankguarantees excellent corrosion resistanceas much on the outer surface as in its hollowsections.AThe A-class surface quality of THE TubularBlank allows the application of hydroformedparts for visible components.The specific production process ofTHE Tubular Blank offers the uniquepossibility of using the best of differentmetals for various applications.Utilising benefits togetherIntegration of components, cost reduction, weight reduction, bettercrash performance, realisation of space frame concepts, efficient useof material... these are all well-known targets of hydroforming within theAutomotive Industry. THE Tubular Blank has now brought the benefitsof this technology even closer. THE Tubular Blank can overcome manyexisting barriers and opens the door wide to hydroforming. So let'smake the most of this opportunity and utilise the benefits together.Corus Hyfo gladly offers its material know-how, hydroforming expertiseand engineering assistance wherever required.