A new high-strength steel grade
“We embarked on the challenging journey to develop a new high-strength steel grade called Docol 1000CP,” he continues, adding that the specific chassis grade did not exist at the time.
While the team members from both Gestamp and SSAB admit that the seven years that followed had more than their fair share of bumps in the road, they all emphasize that the end result – an innovative new steel grade that delivered what the product required in terms of local and global formability, strength, stiffness and fatigue – came about as the result of an exceptional collaborative effort on both sides.
“This is exactly how SSAB like to work: to be invited right at the start of the project. The combination of SSAB’s material knowledge and Gestamp’s design and manufacturing experience have both been so important in turning this concept into reality,” says Ben Cook, sales segment manager from SSAB.
“We were able to try a huge number of different compositions thanks to SSAB’s flexibility and quick turnaround when it came to the prototype materials,” adds Carlota Arenillas, innovation project manager at Gestamp Chassis Spain.
Over the course of the project, Gestamp worked closely with SSAB on everything from material composition to characterization and, finally, homologation of the material for use on a front lower control arm (FLCA).
It was a true team effort, in which every aspect of the development chain was involved – from sales to production to customer trials and feedback – and one which both teams now view as a unique example of cross-company collaboration in the world of steel development.
So, what exactly is the new steel grade?
Docol® 1000CP is significantly higher in strength than conventionally used grades, without compromising on quality, performance or part geometry. This enables a thinner gauge making the part lighter. The strength and ductility originate from the complex phase microstructure. Along with a good surface quality and high strength, the steel also performs well in fatigue; an important property for FLCA components.
“In practice, this new material has enabled us to deliver a front low control arm that is significantly lighter than its predecessor,” states Dr. Asadi. “And we all know by now that a lower weight in the automotive industry means enhanced fuel efficiency and fewer emissions.”