Acta Metallurgica Sinica (English Letters) ›› 1999, Vol. 12 ›› Issue (2): 155-159.

• Research paper • Previous Articles     Next Articles

MECHANISM OF SECONDARY M_(23)C_6 PRECIPITATION AROUND MC IN A COBALT-BASE SUPERALLOY

W.H. Jiang;X.D. Yao;H.R. Guan and Z.Q. Hu(1) Department of Superalloys, Institute of Metal Research, The Chinese Academy of Sciences, Shenyang 110015, China2) Department of Metal Materials Engineering, Shenyang Polytechnic University) Shenyang 110023, China )Manuscript received in revised form 11 September 1998   

  • Received:1999-04-25 Revised:1999-04-25 Online:1999-04-25 Published:2009-10-10

Abstract: Secondary M23C6 precipitation around primary MC carbide in a directionally solidified cobalt-base saperalloy was investigated duriny aging at 850℃. The results show that it was closely related to the decomposition of the MC. Two mechanisms were suggested,i.e. the in situ reaction, MC+γ→M23C6+C, and the direct reaction, M+C→M23C6,in which MC acted as a carbon source.

Key words: cobalt-base superalloy, secondary precipitation, carbide, aging