Heat-Resistant Ferritic Stainless Steel with High Formability for Automotive Exhaust Gas Systems

Improved formability and higher heat-resistance are increasingly demanded to materials used for hot end parts of automotive exhaust gas system in order to meet stricter emission regulations. A heat-resistant ferritic stainless steel and pipe with high formability was developed by refining the microstructure of hot rolled and annealed sheets. The newly developed steel showed a remarkable improvement in various forming properties such as limit drawing ratio, limit expansion ratio of pipe, and thickness reduction ratio of pipe after bending in comparison with conventional steels.