Determination of the liquidus and solidus temperatures of FeCrAl stainless steel

Abstract

The liquidus and solidus temperatures of FeCrAl stainless steel were determined by differential scanning calorimetry (DSC) at different heating rates. They were also calculated by Thermo-calc software and empirical formulae separately. The accuracy of calculation results was assessed by comparison with the corresponding DSC results. The liquidus temperatures calculated by empirical formulae, which exhibited a maximum deviation of 8.6°C, were more accurate than those calculated using Thermo-calc, which exhibited a maximum deviation of 12.11°C. On the basis of Thermo-calc calculations performed under the Scheil model, the solidus temperature could be well determined from solid fraction (f S ) vs. temperature (t) curves at f S = 0.99. Furthermore, a theoretical analysis to determine the solidus temperature with this method was also provided.

Simulation of the Solidification and Microstructural Evolution in Steel Casting Processes Using the InterDendritic Solidification Tool

“…Table 7 shows the deviation obtained between the experimental [22,52,82,84,[86][87][88]90,92,93,95,96,99,[102][103][104][105][106][107][108][109][110][111]128,[130][131][132] and calculated solidus temperatures for 75 low-alloyed and 103 high-alloyed (stainless) steels. The average deviation between the calculated and the measured temperatures is as high as 10.3 °C but due to the aforementioned poor accuracy in the measuring technique, the correlation can be considered reasonable.…”

“…From all phase‐change temperatures, the liquidus temperature can be most accurately measured. Table 2 and 3 show the average deviation () obtained between the experimental [ 22,37–112 ] and calculated liquidus temperatures for 283 ternary Fe–X–C alloys (Table 2), 274 ternary Fe–Cr–X and Fe–Ni–X alloys (Table 2), 55 ternary Fe–X–Y alloys (Table 2 ), as well as 410 low‐alloyed (143) and high‐alloyed (267) steels (Table 3). The average deviations in the predicted liquidus temperatures are 5.6 °C for carbon alloys, 3.9 °C for Cr and Ni alloys, and 11.8 °C for other alloys (Table 2), while the average deviation for the low‐ and high‐alloyed steels was 3.2 °C (see Table 3).…”

Thermodynamic analysis of inclusion characteristics in as-cast FeCrAl-(La) alloys

“…where f s is the solid fraction, and k is the equilibrium partition ratio: k = 0.98 for Al, k = 0.27 for N [23]. Han et al [24] have measured the solidification start temperatures for the FeCrAl alloys by the DSC method; the measured results were around 1800 K. Thus, the thermodynamic calculation for AlN formation in the Fe-20Cr-5Al-0.006N system is at 1800 K. Figure 6 shows the variation of the activity product of Al and N with the solid fraction (f s ). The calculated critical value for AlN precipitation is indicated by the red broken line.…”

Estudo da cinética de geração de hidrogênio por reação metal-água em ligas de revestimento de combustível aplicadas em reatores nucleares.

“…Apesar da melhor resistência à oxidação em altas temperaturas, aços ferríticos e martensíticos a 475 ºC proporcionam a formação da fase ' na fase ferrita () por precipitação ou decomposição espinoidal, cujo efeito é a fragilização da liga (TERADA et al, 2008) Como possuem excelente resistência à oxidação, o fator limitante para a integridade dos revestimentos de combustível em ligas de FeCrAl é a sua temperatura liquidus, de aproximadamente 1500 °C (HAN et al, 2015;(MERRILL;BRAGG-SITTON;HUMRICKHOUSE, 2017).…”