Effect of heat treatment on transformation-induced plasticity of economical Cr19 duplex stainless steel

Effect of annealing recrystallization treatment from 950 to 1250 degrees C for 3 min and isothermal aging heat treatment at 750 degrees C for 1 -7 h on transformation-induced plasticity (TRIP) of economical Cr19 (Fe-19.1Cr-1.3 Ni-6.2Mn-1.0Mo-0.173N-0.027C-0.37Si) duplex stainless steel (DSS) has been investigated mainly by transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD). Economical Cr19 DSS exhibited almost 1100 MPa in ultimate tensile strength and an elongation to fracture of exceeding 50% in elongation when annealing recrystallization temperature was 1050 degrees C, with a sequential martensite transformation of c? e-martensite ? a0-martensite during tensile deformation. All annealed specimens exhibited moderate strain hardening, but became less obvious with the increase of annealing recrystallization temperature. Isothermal aging treatment at 750 degrees C of the 1050 degrees C annealed recrystallization specimens increased the ultimate tensile strength of Cr19 TRIP DSS with the increase of aging time, mainly due to the precipitate of Cr23C6 at ferrite-ferrite grain boundary. (C) 2013 Elsevier Ltd. All rights reserved.