Japan's JFE Steel Corporation, one of the world's leading integrated steel producers, and Germany's largest steel maker, thyssenkrupp Steel Europe, have jointly launched a new 980 and 1180MPa class high-strength steel for cold forming.
These products represent higher yield strength and higher ductility, especially excellent local ductility, compared to conventional high-tensile steels. These characteristics contribute to further weight reduction of the automobile body frame (Body in White) and better crash safety performance, and also to higher productivity and lower manufacturing costs at customers because the complicated components can be formed by conventional cold (press / roll) forming process without using hot stamping process.
In the current automobile vehicle design, it is required to achieve energy saving, weight reduction for reducing CO2 emissions and crash safety performance at a same time. However, the higher strength of steel for weight reduction inevitably results in its inferior formability, and thus it has been difficult to apply higher strength steel to more complicate components.
To overcome this challenge, JFE and thyssenkrupp Steel have developed these products by designing a new steel composition & microstructure especially focusing on the local ductility of steel and by establishing a new heat treatment method utilizing the Quenching & Partitioning process 1. JFE and thyssenkrupp Steel have a wide range of intellectual properties regarding these new products and manufacturing process, and these products can be supplied globally by JFE and thyssenkrupp Steel for automobile applications. The strength level of products are 980 and 1180MPa, with various type of coating, uncoated, galvannealed, and galvanized. These new products are designed for the wide applications to next-generation vehicles including battery electric vehicles. In addition, JFE and thyssenkrupp Steel continue to jointly develop products with even higher strength level.
JFE and thyssenkrupp Steel will continue to contribute to more sustainable society through these products, which realize better passenger safety and higher fuel efficiency (less CO2 emission) by the weight reduction of vehicles.
1 Quenching & Partitioning Process
A metallurgical process that stabilizes at room temperature by quenching and reheating the austenite phase, which is produced at high temperatures and contributes to ductility.