Rafael,
There is no absence of metallographic literature on austenitic SS's. The available literature could fill the parking garage of the Sears tower. But you most likely willnot find it free. ASM, IIW, AWS Journal Research supplemnts, WRC, Abington Publishing, TWI, Woohead Publishing, and many others have volumes upon volumes of not only metallographic imaging of austenitics but how to achieve those images and what they mean.