The new Lancia Thesis features the first-ever volume application of hydroformed engine cradles made from laser-welded tubing.
Corus Hyfo is supplying the tube. Tower Automotive is hydroforming it. Production has already started and volumes of 20,000 a year are expected at full capacity.
Hydroformed engine cradles have become more common because they replace multiple parts that must otherwise be combined. But none of the other applications requires such high strength as the Lancia Thesis, which is why laser-welded tubing was necessary.
'Conventional tube made by electrical resistance welding simply could not meet the demands of the Lancia application,' said Kevin Edgar, product and market development manager.
Hydroforming uses hydraulic pressure to press metal into a mold, allowing more complex and deeper draws than conventional stamping.
Corus Hyfo will produce the tube in the Netherlands for Lancia.
But Corus could set up other manufacturing facilities in North American within a few years. The company has just announced a joint venture with Novamerican Steel to explore the potential of the market there.
Corus Hyfo said its laser-welded tube offers potential for weight savings in other areas of the car body. Roof rails and roof cross-members are potential hydroformed parts because greater diameter-to-thickness ratios are possible than with conventional tube.
Corus is not the only steel company to develop laser-welded tube technology. ThyssenKrupp Stahl is also working on laser-welded tubes.
In addition, the potential of welding the tube from different grades and thicknesses of steel to form a tailored tube creates opportunities in the crash structure of a vehicle. Corus Hyfo sees conical tubing as another potential for automotive applications.
'For vehicle sections that are narrow at one end and broad at the bottom end, you can hydroform them from a conical tubular blank,' Edgar said. 'Door pillars are a good example. They have a very narrow section at the top so as not to obscure passenger visibility, and broad sections at the bottom where they join onto the lower body structure.'