摘要
采用OM,SEM,TEM和EPMA,对Ti和Al含量不同的Fe-Ni基合金在900—1030℃固溶温度范围内的η相析出行为进行了研究.结果表明,η相的形成与合金中的Ti含量和Al含量密切相关,提高(Ti+Al)含量或Ti/Al比,可增加η相的析出倾向;在980℃固溶处理后,低(Ti+Al)含量和Ti/Al比的合金中不存在η相,而在高(Ti+Al)含量和Ti/Al比的合金中仍存在η相;随合金(Ti+Al)含量或Ti/Al比的增加,γ'相可在更高温度存在,在高温固溶处理过程中,η相消耗合金中的γ'而析出并长大;合适的固溶温度可消除合金中的元素偏析和抑制η相的析出.
Fe-Ni base austenitic alloys have been widely used as structural materials in the hydrogen environment, which is strengthened by the precipitation of γ＇[Ni3 （Al, Ti）]. η phase is present after solution treatment in some modified alloys, which is detrimental to hydrogen resistance performance of alloys. In order to eliminate the η phase and optimize the alloy composition, the precipitation behavior of η phase in Fe-Ni base alloys with different Ti and Al contents was investigated in the range of 900 ℃ to 1030 ℃ using OM, SEM, TEM and EPMA. The results show that the formation ability of η phase is related to the content of Ti and Ah Increasing the （Ti＋Al） content or the Ti/A1 ratio in the alloys promotes the precipitation of η phase. Moreover, the U phase does not exist in alloys with the lower （Ti ＋Al） content or Ti/A1 ratio, but still presents in the alloys with higher （Ti＋A1） content and Ti/Al ratio after the standard solution treatment at 980 ℃, which is due to that the phase precipitates at the expense of the γ＇ phase existing at higher temperature. In situ microstructure observations indicate that η phase and elemental segregation can be eliminated by the optimization of solution treatment condition.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期1335-1341,1,共7页
Acta Metallurgica Sinica
基金
国家自然科学基金项目51171178和u1230118资助~~
关键词
Fe—Ni基合金
Η相
固溶处理
析出行为
Fe-Ni base alloy, U phase, solution treatment, precipitation behavior
