Beitrag zum System Eisen–Stickstoff–Kohlenstoff

Abstract

Durch Aufstellung isothermischer Schnitte bei 500 bis 700 °C Untersuchung der heterogenen Gleichgewichte in der Eisenecke des Systems Eisen–Stickstoff–Kohlenstoff bei 500 bis 700 °C. Veränderungen der Gitterkonstanten der ε‐Phase durch Kohlenstoffaufnahme.

Thermodynamics of the Fe-N and Fe-N-C Systems: The Fe-N and Fe-N-C Phase Diagrams Revisited

“…For the binary system Fe-N, the data as assembled in Reference 12 [25,35,36,[66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85] was chosen according to the recommendations given there. The binary thermodynamic descriptions of the a and c phase were taken from Reference 22; for the choice of parameters to be optimized, see Section IV.…”

“…Various enlarged sections of the phase diagram are shown in Figure 2 to allow a more detailed comparison with both the experimental data [13,15,25,35,36,66,67,[70][71][72][73][74][75][76][78][79][80][81][82]84,87,88] and the previous predictions from References 22 and 24.…”

“…[24] describes c 0 as a stoichiometric compound with the formula Fe 4:1 N. (d) The c 0 + e/e phase boundary compared with experimental data from Refs. [36,66,67,70,71,74,79] and [87]. Also, the phase boundary redrawn from Fig.…”

“…Furthermore, the appearance of c is concluded to occur at a temperature as low as 838 K (565°C) in Reference 36, in flagrant contrast with later experimental data. [15] In contrast to these early experimental works, [34][35][36] the observation of microstructures forming upon nitriding of Fe-C alloys and C-containing steels and upon nitrocarburizing pure Fe, Fe-C alloys, and C-containing steels, which do contain interfaces between a and e [37][38][39][40][41][42][43][44][45][46][47] makes it very likely that equilibrium between a and e does occur, albeit in a narrow temperature range. Later works [15,[48][49][50][51][52][53] confirmed the occurrence of such microstructures.…”

The $$\upalpha +\upvarepsilon $$ Two-Phase Equilibrium in the Fe-N-C System: Experimental Investigations and Thermodynamic Calculations

“…[1] Probably, the most influential study on solidstate equilibria in this ternary system was performed by Naumann and Langenscheid. [2] They presented isothermal sections of the Fe-N-C phase diagram at 1Â10 5 Pa between 773 K and 973 K (500°C to 700°C). This work was the main reference to the later reviews in References 3 through 5.…”