GH4151合金的凝固偏析行为及均匀化热处理研究
Solidification Segregation Behavior and Homogenization Heat Treatment of GH4151 Alloy
盖永超 1张瑞 1周子荐 1吕少敏 2崔传勇 1曲敬龙2
作者信息
- 1. 中国科学院金属研究所师昌绪先进材料创新中心,辽宁沈阳 110016
- 2. 钢铁研究总院高温材料研究所,北京 100081;北京钢研高纳科技股份有限公司,北京 100081
- 折叠
摘要
GH4151合金是一种承温能力高达800℃的新型涡轮盘用铸锻变形高温合金,该合金在凝固过程中元素偏析严重,主要偏析元素包括Nb、Mo和Ti等元素,同时合金中包含大量的C元素,在熔炼凝固后期由于残余液相中的元素富集,枝晶间会析出大量有害相,包括(γ-γ')共晶,Laves相,η相和MC碳化物.实验通过研究C含量对各偏析元素的影响发现,增加C含量可减轻Nb元素在枝晶间的偏析,此外,随C含量的增加枝晶更发达,枝晶间区域减少.随后通过研究在1160～1210 ℃不同温度下的均匀化热处理对各枝晶间析出相的影响发现,(γ-γ')共晶和Laves相的熔点约为1180 ℃,η相的熔点约为1200 ℃,MC碳化物的熔点超过1300℃;同时,发现1170 ℃/16 h+1200 ℃/8 h双步均匀化热处理不仅可以消除铸锭中的偏析,而且避免了低熔点相过烧而产生的孔洞,使坯料更加有利于后续开坯变形.
Abstract
GH4151 alloy is a new type of casting and deformation superalloy of turbine disk with the temperature bearing capacity up to 800 ℃.The alloy has severe elemental segregation during solidification,and main segregation elements include Nb,Ti and Mo.Meanwhile,the alloy contains a large amount of element C.In the late stages of solidification,due to the enrichment of elements in the residual liquid phase,a large number of harmful phases,including(γ-γ')eutectic,Laves phase,η phase and MC carbides,precipitate between the dendrites.The influence of C content in the GH4151 alloy on the segregation elements was investigated.Result show that increasing C content can reduce the segregation of Nb elements between dendrites.In addition,with the increase in C content,the dendrites become more developed and the interdendrite area decreases.The effects of homogenization heat treatment were studied at different temperatures from 1160 ℃ to 1210 ℃.The melting points of(y-y)eutectic and Laves phases are about 1180 ℃,that of η phase is about 1200 ℃ and that of MC carbide is higher than 1300 ℃.At the same time,it is found that the 1170 ℃/16 h+1200 ℃/8 h double step homogenization heat treatment can not only eliminate the segregation in the ingot,but also avoid the holes caused by the overburning of the low melting point phases,which makes the billet more conducive to the subsequent billet deformation.
关键词
变形高温合金/凝固偏析/有害相/均匀化Key words
wrought superalloy/solidification segregation/harmful phases/homogenization引用本文复制引用
基金项目
国家科技重大专项(2019-VI-0006-0120)
国家重点研发计划(2019YFA0705300)
国家重点研发计划(2017YFA0700703)
中国科学院金属研究所创新基金(2021-PY09)
辽宁省博士启动基金(2020-BS-007)
出版年
2024
NETL
NSTL
万方数据