Ford has selected ArcelorMittal’s Fortiform 980 GI (earlier post) as the sole source of third-generation advanced high-strength steel (Gen 3/HF) for the revitalized 2021 Ford Bronco. This highly anticipated vehicle will be the first automobile in the world to incorporate this grade of steel, which is made at AM/NS Calvert in Alabama.

The family of Fortiform steels extends ArcelorMittal’s range of Ultra High Strength Steels (UHSS). These steels allow the realization of lightweight structural elements by a cold forming method such as stamping. These Ultra High Strength Steels of third generation are used to provide additional weight reduction thanks to their higher mechanical properties than conventional Advanced High Strength Steels (AHSS) while keeping the same formability.

Position of Fortiform steels in the ArcelorMittal steel range

Ford’s main objectives were to create a lightweight and safe vehicle and the company enlisted ArcelorMittal to achieve these critical goals.

Ford called us to see if we could develop this specific type of steel. We were actually already in the development phase so we discussed the opportunities as well as where they could utilize this material and for which vehicle. Ford’s chief engineer gave us a goal to decrease the total vehicle weight reduction by 10%. In terms of safety, we selected a higher strength material which gives Ford a huge safety advantage.

—Michael Lizak, ArcelorMittal global technology coordinator for Ford at Automotive Product Applications R&D

Ford places a huge priority on the ductility of steel and this grade comes from a family of high formability grades, meaning it has an excellent balance of both strength and ductility. In addition, the weldability was superior to the competition.

After performing an inclusive weld study with Ford, it was clear that Fortiform 980 GI could weld to it itself and to most other steels. Additionally, Ford’s lightweighting strategy and safety requirements align with this solution. The high strength steel is a lower gage than the original DP800 and DP600 found in the earlier Bronco, which enables weight savings with complex shape through better formability.

ArcelorMittal’s co-engineering capabilities, which fostered the close collaboration between ArcelorMittal R&D and Ford’s design and welding experts played a pivotal role in this project.

We had a product, that was engineered to have very good weldability desired by Ford. Ford conducts many tests before granting the product application ready status (AR). No other steel grade had been tested this much because this steel grade was so new and unique.

—Jayanth Chintamani, director, automotive product research, ArcelorMittal R&D

ArcelorMittal R&D in East Chicago was charged with the product design.

From a process perspective, because this was a coated product, we enlisted the coating experts on my team along with the product design experts. We then made sure that the target-critical processing parameters during various stages of industrial manufacturing were met with support from process experts at R&D as well.

—Jayanth Chintamani

The R&D team also worked closely with the joint venture (JV) partners at AM/NS Calvert as the steel is made on their upgraded line.