Evolution of Precipitate Phases During Long-Term Isothermal Aging at 1083 K (810 °C) in a New Precipitation-Strengthened Heat-Resistant Austenitic Stainless Steel

Creep behavior and microstructure evolution at 750°C in a new precipitation-strengthened heat-resistant austenitic stainless steel

“…The observed superior high-temperature dimensional stability and stable quantities of Z-phase precipitates and of their (Nb,Cr)N precursory phase during the conducted creep tests demonstrated excellent creep-strengthening capability of the particles. Furthermore, the transformation of (Nb,Cr)N precipitates to Z-phase precipitates is essentially desirable for long term creep strength of the steel since Z-phase precipitates are more coarsening-resistant comparing to (Nb,Cr)N precipitates with fcc crystal structure [27]. The wide range of particle sizes observed for copper precipitates in the present study and associated increase in their sizes with the prolonging creep exposure time (see Figs.…”

“…The particles' excellent dimensional stability which exceeds even that of g' precipitates in advanced Ni-based superalloys, retains even at temperatures as high as 810 1C [27]. Essentially, the precipitates played a major role in the observed outstanding creep behavior of the studied steel.…”

The Effect of Aging on Precipitates, Mechanical and Magnetic Properties of Fe-21Cr-15Ni-6Mn-Nb Low Magnetic Stainless Steel

“…Therefore, it needs further observation and analysis to identify the precipitates. In terms of composition, the contents of Cr and N are usually higher in Z phase [26]. In addition, the precipitates in the grain were spherical or ellipsoidal (Figure 5a), while the Z phase is usually rod-shaped [27,28].…”

“…In this experiment, combined with the TEM diffraction spot calibration, it can be further determined that the precipitated particles are (Nb, V)(C, N) of the facecentered cubic structure and have a cube-on-cube orientation relationship with the austenite matrix. Z phase particles have a body-centered cubic (BCC) structure, which are easily formed in steels containing high Cr, high Nb and high N [26]. Once the Z phase arises, it will grow up at a rapid speed with the cost of MX-type carbonitrides, and it is difficult to control the size, which is not beneficial to the strength of the steel.…”

New Creep-Resistant Cast Alloys with Improved Oxidation Resistance in Water Vapor at 650–800°C

“…Creep properties of CF8CP steel can be further improved as is found in some stainless steels by adding Cu to form nanoscale Cu precipitates (Sawaragi and Hirano, 1990;Swindeman et al, 1990;Wu et al, 2005;Chi et al, 2012;Ha and Jung, 2012). The new version of CF8CP, called CF8CWCu, with~3% of Cu and~1% of W for solution strengthening, has demonstrated even better creep properties, similar to more expensive Ni-based alloys such as alloy 625 and 617 (Shingledecker et al, 2005;Maziasz and Pint, 2011).…”