Work Hardening Behavior in Steel with Multiple TRIP Mechanisms
Transformation-induced plasticity (TRIP) behavior was studied in steel with the composition Fe-0.07C-2.85Si-15.3Mn-2.4Al-0.017N that exhibited two TRIP mechanisms. The initial microstructure consisted of both ε- and α-martensites with 27 pct retained austenite. TRIP behavior in the first 5 pct strain was predominately austenite transforming to ε-martensite (Stage I), but upon saturation of Stage I, the ε-martensite transformed to α-martensite (Stage II). Alloy segregation also affected the TRIP behavior with alloy-rich regions producing TRIP just prior to necking. This behavior was explained by first-principles calculations which revealed that aluminum significantly affected the stacking fault energy in Fe-Mn-Al-C steels by decreasing the unstable stacking fault energy and promoting easy nucleation of ε-martensite. The addition of aluminum also raised the intrinsic stacking fault energy and caused the ε-martensite to be unstable and transform to α-martensite under further deformation. The two-stage TRIP behavior produced a high strain hardening exponent of 1.4 and led to an ultimate tensile strength of 1165 MPa and elongation to failure of 35 pct. © 2013 The Minerals, Metals & Materials Society and ASM International.
M. C. McGrath et al., "Work Hardening Behavior in Steel with Multiple TRIP Mechanisms," Metallurgical and Materials Transactions A, ASM International, Jan 2013.
The definitive version is available at http://dx.doi.org/10.1007/s11661-013-1820-x
Materials Science and Engineering
Article - Journal
© 2013 ASM International, All rights reserved.