The present invention relates to the use of a hot workable ferritic stainless steel alloy resistant to thermal cyclic stress and oxidation at elevated temperatures and having improved mechanical properties as substrate for exhaust gas purifying applications, such as catalytic converters or heating applications and having the following composition (in weight-%): C <=0,05%, Cr 16,0-24,0%, Ni more than 1,0-15,0%, Al 4,5-12,0%, Mo+W <=4,0%, Mn <=1,0%, Si <=2,0%, Zr+Hf <=0,1%, REM <=0,1%, N <=0,05% balance Fe and normally occurring steelmaking impurities and additions.