Journal or Book Title
Metallurgical and Materials Transactions A
The isothermal formation behavior of secondary phases in two types of duplex stainless steels (DSS), CD3MN and CD3MWCuN, was characterized. Samples were heat treated from 1 minute to 30 days at temperatures from 700°C to 900°C. Small carbide (M23C6) and nitride (Cr2N) precipitates, together with the intermetallic phases sigma and chi, were observed using scanning electron microscopy (SEM) and confirmed by transmission electron microscopy (TEM) analyses. Based on SEM analysis, time-temperature-transformation (TTT) curves for the sigma and chi phases were determined by measuring their volume fractions from backscattered electron micrographs of heat-treated and quenched sample cross sections. Resulting TTT curves showed that the maximum formation temperature for chi is lower than that for sigma, while the time to reach 1 vol pct formation is much less for sigma than it is for chi. The thermodynamic driving forces associated with the sigma and chi formation were assessed using Thermo-Calc.
Copyright 2007 ASM International. This paper was published in Metallurgical and Materials Transactions A, Vol. 38, Issue 2, pp. 203-211 and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.
Kim, Yoon-Jun; Ugurlu, Ozan; Jiang, Chao; Gleeson, Brian; and Chumbley, L. Scott, "Microstructural Evolution of Secondary Phases in the Cast Duplex Stainless Steels CD3MN and CD3MWCuN" (2007). Materials Science and Engineering Publications. 145.