The orientation dependence of γ-α' martensitic transformation in austenitic stainless steel single crystals with low stacking fault energy

The gamma-alpha' martensitic transformation (MT) during tensile deformation in austenitic stainless steel single crystals of Fe-17% Cr-12% Ni-2% Mn-0.75% Si (wt.%) with low stacking fault energy has been investigated in dependence on crystal axis orientation and test temperature T=77-300K by means of X-ray diffraction analysis and transmission electron microscopy. In this steel the gamma-alpha' MT is shown to occur during plastic deformation at T <= 190 K and after the gamma-epsilon MT. The orientation dependence of slip deformation prior to the MT results in the development of gamma-alpha' MT in [(1) over bar 11]-, [011], [(1) over bar 23]- [012]-crystals with a different defect structure. It is shown that in [(1) over bar 11]-, [111], [(1) over bar 23]-, [012]-crystals the gamma-alpha' MT might occur at T= 300 K but after pre-deformation at T= 77 K. (c) 2007 Elsevier B.V. All rights reserved.