TY - JOUR
T1 - Development of a Novel Heat-Resistant Austenitic Cast Steel with an Improved Thermal Fatigue Resistance
AU - Martinez Carreon, B. A.
AU - Ramos Azpeitia, M. O.
AU - Hernandez Rivera, J. L.
AU - Bedolla Jacuinde, A.
AU - Garcia Lopez, C. J.
AU - Ruiz Ochoa, J. A.
AU - Gonzalez Castillo, A. C.
N1 - Publisher Copyright:
© 2022, American Foundry Society.
PY - 2023/4
Y1 - 2023/4
N2 - In this work, the Thermo-Calc software was used to evaluate the effect of the Nb and Mn additions on the thermal phases stability for a conventional HT heat-resistant austenitic cast steel (HRACS) at high temperature. The simulations show that addition of Nb promoted the decrease in carbides (Fe, Cr)7C3 and Cr23C6 as well as the formation of a stable NbC at elevated temperature. Meanwhile, the Mn addition does not modify the amount of Cr23C6 and (Fe, Cr)7C3 and tends to reduce the (Fe, Cr)7C3 to Cr23C6 transformation temperature. In order to validate the thermodynamic simulations, specimens of an austenitic cast steel modified with 3.3 wt% of Nb were fabricated, characterized and compared with specimens of conventional HT steel after the application of 25, 50 and 100 continuous heating–cooling cycles in non-protected atmosphere. It was found that the Nb causes the reduction of phases that promoted the nucleation of thermal microcracks, which was in good agreement with simulations. In addition, the results indicated that Nb allowed the reduction of the number, length and propagation rate of microcracks. Therefore, this novel HRACS demonstrated to be more resistant to thermal fatigue compared to conventional HT steel in a non-protected atmosphere.
AB - In this work, the Thermo-Calc software was used to evaluate the effect of the Nb and Mn additions on the thermal phases stability for a conventional HT heat-resistant austenitic cast steel (HRACS) at high temperature. The simulations show that addition of Nb promoted the decrease in carbides (Fe, Cr)7C3 and Cr23C6 as well as the formation of a stable NbC at elevated temperature. Meanwhile, the Mn addition does not modify the amount of Cr23C6 and (Fe, Cr)7C3 and tends to reduce the (Fe, Cr)7C3 to Cr23C6 transformation temperature. In order to validate the thermodynamic simulations, specimens of an austenitic cast steel modified with 3.3 wt% of Nb were fabricated, characterized and compared with specimens of conventional HT steel after the application of 25, 50 and 100 continuous heating–cooling cycles in non-protected atmosphere. It was found that the Nb causes the reduction of phases that promoted the nucleation of thermal microcracks, which was in good agreement with simulations. In addition, the results indicated that Nb allowed the reduction of the number, length and propagation rate of microcracks. Therefore, this novel HRACS demonstrated to be more resistant to thermal fatigue compared to conventional HT steel in a non-protected atmosphere.
KW - characterization
KW - heat-resistant steels
KW - thermodynamic simulation
UR - http://www.scopus.com/inward/record.url?scp=85133575513&partnerID=8YFLogxK
U2 - 10.1007/s40962-022-00838-1
DO - 10.1007/s40962-022-00838-1
M3 - Artículo
AN - SCOPUS:85133575513
SN - 1939-5981
VL - 17
SP - 1114
EP - 1127
JO - International Journal of Metalcasting
JF - International Journal of Metalcasting
IS - 2
ER -