Acta Metallurgica Sinica (English Letters) ›› 1991, Vol. 4 ›› Issue (3): 172-176.

• Research paper • Previous Articles     Next Articles

METASTABLE R-PHASE IN Fe-Cr-Mo AND Fe-Cr-W ALLOYS

LIU Shicheng Dalian Railway Institute,Dalian,ChinaHAMAGOCHI Yoshikazu KUWANO Hisashi Muroran Institute of Technology,Muroran,Japan   

  • Received:1991-06-25 Revised:1991-06-25 Online:1991-06-25 Published:2009-10-10

Abstract: The precipitation behaviour of Fe-Cr-Mo and Fe-Cr-W alloys during aging has been ex- perimentally studied.It was found that in the early stage of aging,a metastable R phase pre- cipitated in both alloys,it was transformed into stable μ-phase,Laves-phase,X-phase or σ-phase in the later stages.The crystallographic structure of metastable R-phase is rhombohedral with lattice parameters of a=0.9075 nm and α=74.45°.The chemical compo- sition of R-phase is Fe-(27.5—34.9)Mo-(0—25.5)Cr and Fe-(28.9—33.0)W-(9.36— 21.0)Cr in at.-% in Fe-Cr-Mo and Fe-Cr-W system,respectively.

Key words: Fe-Cr-Mo alloy, Fe-Cr-W alloy, precipitation, metastable R-phase