As automakers are challenged to improve safety and fuel economy, they continue to search for new materials to meet the higher performance demands of body structures. Working with its automotive partners, ArcelorMittal is responding to that challenge, adding to its family of advanced high strength steels (AHSS) for the auto industry.

With the development of GI Fortiform® 980, the limitations that body engineers had experienced when using second-generation higher strength steel grades for parts that play a role in energy absorption, or parts that were complex in shape, are eliminated.

“The new GI Fortiform® 980 range of AHSS for cold stamping combines superior formability and ductility at higher strengths that exceed the capabilities of the second-generation AHSS, thus opening up significant new opportunities for AHSS in body engineering,” said Hassan Ghassemi-Armaki, lead research engineer, Global Research and Development, East Chicago. “This is a crucial advantage as carmakers come under pressure to further lighten vehicles as a part of their strategy to improve fuel economy.”

“Because of its superior properties, GI Fortiform® 980 could help achieve weight savings of up to 20% compared to conventional AHSS while meeting increasingly stringent crash and safety requirements,” said Qaiser Khan, senior engineer, Global Research and Development, East Chicago. “This grade is suitable for use in many structural parts of the vehicle that are affected during impact, including front and rear rails.”

The GI Fortiform® 980 1.4mm gauge axial crush results.

GI Fortiform® 980 is compatible with the current welding systems used in the industry. The product was engineered to mitigate the challenges typical of higher strength AHSS such as liquid metal embrittlement and optimum weld strength. ArcelorMittal has studied four welding types - resistance spot-welding, laser welding, MIG brazing and gas metal arc welding - with no signs of surface cracks in critical zones.

The new steel grade was showcased in a presentation titled ‘On the Advantages of Fortiform® 980 GI - A Third Generation AHSS Grade with Superior Weldability’ presented by authors, Ghassemi-Armaki, Khan and Shri Aditya Varanasi from ArcelorMittal USA, at the 2019 Great Designs in Steels (GDIS) conference. The presentation also discusses axial crush results of this grade for different gauges and weld pitch combinations.

GI Fortiform® 980 joins grades Fortiform® 1050 and Fortiform® 1180. The successful launch of these AHSS grades over the past six years is further proof that steel is the most sustainable, adaptable and most affordable material to help automakers produce lighter vehicles and achieve their weight reduction targets on-time without compromising strength and safety. It demonstrates that ArcelorMittal has an unwavering focus on delivering value to the industry and the products it needs into the future.