C含量对IC6合金微观组织的影响

Effect of Carbon Content on Microstructure of IC6 Alloy

利用带能谱的扫描电镜分析研究了三种C含量IC6合金的铸态组织及1260℃/10h固溶处理后的微观组织及微区成分,并利用X射线衍射仪分析了合金中的相结构。结果表明,三种不同C含量IC6合金的铸态组织主要由γ′,γ,NiMo,-αMo,M3B2及M6C相组成,NiMo,-αMo,M3B2和M6C相呈骨架状或网络状分布于枝晶间。-αMo,NiMo,M3B2相随C含量的增多明显减少,而M6C相明显增多,当合金中C含量达到0.20%(质量分数)时,-αMo相基本消失。经1260℃/10h固溶处理后,三种C含量合金的微观组织发生明显变化,NiMo,-αMo相消失,M3B2,M6C相由铸态的骨架状、网络状变为条块状。随C含量的提高M6C相明显增多,且在枝晶间连续分布。

The microstructure of alloy IC6 with different carbon contents as-cast and after homoginization at 1260℃ for 10h was studied by SEM with EDS and XRD. The results showed that the microstructure of as-cast alloy was mainly composed of γ′, γ, NiMo, α-Mo, M3B2 and M6C phases. NiMo, α-Mo, Ms B2 and M6 C phases distributed in the interdendrite in bone or net pattern. Quantity of NiMo, α-Mo and Ms B2 phases decreased obviously with increase of C content, and α-Mo phase disappeared when C content reached 0. 20% （mass fraction）, while the amount of M6C increased with increase of C content. Microstructures of the three alloys changed obviously after 1260℃/10h solution heat treatment, and NiMo, α-Mo phases disappeared. The shape of Ms B2 and M6 C transformed from bone and net pattern in as-cast to strip and block pattern. Quantity of M6 C increased obviously with increase of C content, distributing continuously in the interdendrite.