Hyundai Steel Co. had developed a premium 1.5GPa martensitic (MS) steel plate for eco-friendly vehicles, which has a higher crack resistance than any other in the same product category.
South Korea’s No. 2 steelmaker noted that with such strengths, it can be used for various applications, including battery cases for EVs, bumpers, and roof side reinforcements.
The 1.5GPa MS steel plate manufacturing requires a rapid cooling process to secure high strength, but it cracks easily due to hydrogen penetration, thereby limiting commercial use for vehicles.
To overcome such limits, Hyundai Steel developed a string of new technologies to replace rapid cooling and minimize hydrogen penetration while optimizing the mixture of alloying elements.
The developments allowed Hyundai Steel to maintain steel plate strength at 1.5GPa while achieving a flatness of 3 millimeters or less.