Analysis of ridging in three ferritic stainless steel sheets

In the present work, three types of ferritic stainless steel sheets AISI 430A (16%Cr), AISI 430E (16%Cr, 0.36%Nb) and AISI 434 (16%Cr, 1%Mo), known to display different ridging behaviours, were characterised in both microstructure and texture using optical metallography and electron backscatter diffraction techniques. It was concluded that surface microridging is a result of the differential plastic behaviour of {111} < uvw > and {001} < uvw > grain colonies existing in the sheet; severe ridging ( undulations) is a consequence of through thickness texture and microstructure inhomogeneities that lead to grain buckling under internal compressive stresses.