Our ideas for the automotive industry
50 safety-relevant structural components are made each second, churning off the presses of European automotive manufacturers. The pressing plant is a crucial point in automotive manufacturing; highly complex production steps are carried out here. These entail a number of challenges – for example, the higher the strength of the material used, the greater the process-related springback. In the past, compensating for this effect required a great deal of effort.
An innovation in cold forming
What if, though, a single tool could be used for steel grades of strength classes ranging from 600 to 1,200 MPa? Such a solution would always make it possible to produce a dimensionally stable component – without having to make any changes to the parameters or the tool itself.
“Up until now, that’s been impossible in the field of forming technology,” says Martin Kibben, a development engineer at thyssenkrupp Steel’s Duisburg location. However, he and his colleagues in Applications Technology at the company have succeeded in accomplishing just that for the steel market: High-strength steels can now be processed during cold forming – in a reliable, dimensionally stable way. The patented technology that enables this solution is called smartform®.
Forming technology without springback
This innovative method particularly solves the issue of springback. “High-strength steels generally act like springs,” says Dr. Thomas Flehmig, head of the development team at thyssenkrupp Steel. “They can be formed, but sometimes they spring right back as soon as they leave the tool.” This is an important effect to consider because even minimal changes to component geometry have an impact on further processing: “For example, in a car, each component is combined with other components, so the areas where they adjoin have to fit against each other precisely.”
Smart production technology for the automotive industry
smartform® makes it possible to precisely produce even highly complex geometries made of high-strength materials. “The goal was to support the automotive industry in reliably processing our newest materials,” says Flehmig. “However, this technology can also be applied in other sectors.”
It essentially consists of two stages. During the first stage, the steel sheet receives a preform with component geometry that is as faithful to the contour as possible, whereby the springback effect is fully tolerated.
During the second stage, calibration is made to the final geometry. The future component is compressed inside the calibration tool in a targeted way to receive its final contour. This compensates for any undesired springback. The tools for the smartform® method are compatible with all standard systems, and do not differ drastically from conventional equipment in terms of cost.
Highly advantageous bending method
This technology, which is ready for series production, also provides other advantages. “The process is highly robust, which is a big plus,” says Kibben. “During conventional manufacturing, the system sometimes needs to be readjusted after a coil change, which can take a lot of time. smartform® greatly reduces the influence of abrasion or material properties.”
Despite varying input and process variables, the result always remains constant. Moreover, smartform® not only saves customers time and money, but also construction material – and in two ways, at that. During manufacturing, the exact amount of sheet required for forming is used. Unlike with conventional deep drawing, the edge trim is eliminated to the greatest possible extent. Depending on the component complexity, this allows material consumption to be reduced by 15 percent on average.
The bending method even offers potential for lightweight design steelmaking. The material benefits of supplying high-strength steel grades are particularly important for solutions in the automotive industry; for instance, in the production of crash-relevant components. Up until now, these types of steels were not used in large quantities for complex geometries during cold forming, since the requisite process reliability could not be ensured.
Flehmig says: “Thanks to smartform®, these innovative automotive components can now be developed from steels of the next-highest strength class and with a reduced thickness.”
smartform® technology stabilizes the manufacturing process, shortens system downtimes caused by disruptions, reduces material usage, and protects tools. It makes the impossible possible; namely, manufacturing dimensionally stable components in various strengths with just a single tool kit.
smartform® technology stabilizes the manufacturing process, shortens system downtimes caused by disruptions, reduces material usage, and protects tools. It makes the impossible possible; namely, manufacturing dimensionally stable components in various strengths with just a single tool kit.
