Delta ferrite 1

[mali325]

Dear group,
-Which stainless steels have delta ferrit phase during hot rolling?
-what is effects of this phase on hot doctility?
Best Regards

 

[mcguire]

Nearly evry type can have some depending on how its composition has been tuned within the specification. Usually the austenitic grades which have been continuously cast have some 5-10% as cast. This transforms to austenite if they are soaked for hot rolling at a correct temperature, 2280F. If hotter, some ferrite forms and hot ductily decreases leading to slivers, hot tears, edge cracks and other ugly stuff. This also happens with PH grades. Ferritic grades are no problem, unless they get a little austenite mixed in with the ferrite, which will also cause edge cracks. This can ahppen in grades like 430.
Duplex are always big trouble since they are two phase. They fail at austenite-ferrite boundaries. It is mandatory to keep sulfur below 10 ppm to avoid weakening these boundaries and preserve what little strength they have.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/