Carbide reactions and phase equilibria in low alloy Cr–Mo–V steels tempered at 773–993 K. Part I: Experimental measurements
1998; Elsevier BV; Volume: 46; Issue: 1 Linguagem: Inglês
10.1016/s1359-6454(97)00238-3
ISSN1873-2453
AutoresA. Výrostková, Aleš Kroupa, Jozef Janovec, Milan Svoboda,
Tópico(s)Metallurgical and Alloy Processes
ResumoAbstract Carbide reactions and phase equilibria of 2.4Cr–0.7Mo, 2.6Cr–0.7Mo–0.14V, 2.6Cr–0.7Mo–0.3V, and 2.6Cr–1.0Mo–0.3V (wt%) steels tempered at 773–933 K for a maximum of 1000 h were investigated. Carbide particles extracted in carbon replica were analysed by means of electron diffraction and energy-dispersive X-ray spectroscopy. Thermodynamic calculations were used to complement and make accurate the experimental results. The time–temperature diagrams of carbide phase stability were constructed for all investigated steels. Here the M 3 C, M 2 C, M 7 C 3 and MC carbides in various combinations are lined up in sequences, the carbides M 23 C 6 and M 6 C form separate areas. The shape of the M 6 C area is similar to that of the Laves phase in medium alloy steels. In the investigated steels three types of phase equilibria were found: ferrite+M 7 C 3 , ferrite+M 7 C 3 +MC and ferrite+M 7 C 3 +M 6 C+MC.
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