Laser welded blanks (LWBs) are an ideal solution for carmakers who wish to lightweight their vehicles. But many manufacturers are using more steel than they need to obtain the parts required. A new study from ArcelorMittal’s Tailored Blanks division has demonstrated that much higher yields can be obtained from a single coil. By optimizing the number of blanks used to form a part, and designing a better layout of the blanks on a sheet of automotive steel, wastage can be reduced dramatically. Using advanced nesting in this way, OEMs can create a more sustainable and cost-efficient production process for vehicle parts.
Optimizing steel usage with advanced nesting opens the door to significant cost reductions for OEMs without affecting the part’s mechanical properties. And it significantly reduces scrap which increases sustainability.
Nesting is commonly used to produce blanks. However, there is room to make this process more efficient and more sustainable for some specific parts. ArcelorMittal has completed a study into an A-pillar to showcase the potential benefits of combining laser welded blank technology and nesting optimization.
A common nesting configuration has been observed at OEMs who produce A-pillar blanks. The configuration places the monolithic blanks face-to-face on the line. The net weight of each monolithic blank is 5.6 kilograms. But due to wastage, 10.6 kg of steel is required to produce each part. Effectively, 48 percent of the steel in the coil is scrapped and recycled. This considerable volume of scrap must be handled and transported for recycling.
Using advanced nesting, OEMs can create two sub-blanks instead of a single monolithic blank. That enables the position of the blanks to be optimized on the sheet and reduces the amount of steel required.
After blanking, the sub blanks are laser welded together to form one part. The position of the weld can be varied, depending on the part’s design. The mechanical properties of the part remain unchanged compared those of a monolithic blank. The net final weight of the part also remains unchanged.
The advanced nesting optimization process provides a range of benefits. For the A-pillar alone, material usage is reduced by almost 30 percent. Cost is also reduced by around €1.00 per car due to the material savings.
And if the volume of steel utilised can be reduced by 30%, the nested LWB solution provides a corresponding 30 percent reduction in CO2 emissions. That emissions reduction is accessible immediately.
Steel is already the leading solution for automotive applications due to its excellent strength-to-weight ratio, cost effectiveness, and inherent recyclability. The combination of advanced nesting and laser welded blanks enhances the sustainability of steel even further by ensuring that scrap is minimised.
While the scrap material can be fully recycled, producing it in the first place generates emissions. By minimising the amount of steel that is required to create a part, these emissions are avoided. And using less steel also reduces costs for automakers as the scrap material does not need to be handled or transported.