抽拉速率对DZ409柱晶高温合金定向凝固组织的影响  

Effect of withdrawal rate on directional solidification microstructure of DZ409 columnar crystal superalloy

作　　者：李杨[1,2] 王晓燕 吴剑涛 吴保平 LI Yang;WANG Xiao-yan;WU Jian-tao;WU Bao-ping(Central Iron&Steel Research Institute,Beijing 100081,China;Hebei Gangyan Dekai Technology Co Ltd,Zhuozhou 072750,China;Beijing Gangyan Gaona Technology Co Ltd,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司,北京100081 [2]河北钢研德凯科技有限公司,河北涿州072750 [3]北京钢研高纳科技股份有限公司,北京100081

出　　处：《材料热处理学报》2025年第3期113-123,共11页Transactions of Materials and Heat Treatment

基　　金：国家科技重大专项(HT-J2019-VI-0020-0136)。

摘　　要：采用高速凝固法(HRS)制备了DZ409柱晶高温合金试板,研究了抽拉速率对DZ409柱晶高温合金定向凝固组织的影响。结果表明:在3种抽拉速率下,均能保证DZ409合金铸件的定向凝固成形,抽拉速率为6 mm/min时,晶粒沿<001>方向整齐排列,晶粒生长更加均匀;随着柱状晶的生长,晶粒数量减少,边缘晶粒逐渐被中心晶粒占据;随着抽拉速率的增加,合金中的一次/二次枝晶间距逐渐减小,γ′相尺寸逐渐减小,且枝晶间的γ′相尺寸始终大于枝晶干处;γ+γ′共晶组织多呈“葵花”状分布,且共晶组织尺寸随着抽拉速率的增加逐渐减小;碳化物的形貌随着生长高度的增加由小块状、条状向骨架状转变,随着抽拉速率的增加,骨架状碳化物逐渐减少,块状、条状碳化物占比不断增加,且尺寸较小、弥散分布。DZ409 columnar crystal superalloy test plates were prepared using high rate solidification(HRS)method,and the effect of withdrawal rate on directional solidification microstructure of the DZ409 columnar crystal superalloy was studied.The results show that directional solidification of the DZ409 alloy castings can be ensured at three different withdrawal rates.When the withdrawal rate is 6 mm/min,the grains are arranged neatly along the<001>direction,and the grain growth is more uniform.As the columnar crystals grow,the number of grains decreases and the edge grains are gradually occupied by the central grains.As the withdrawal rate increases,the primary and secondary dendritic spacing of the alloy gradually decreases,the size of theγ′phase gradually decreases,and the size of theγ′phase in the interdendritic is always larger than that of in the dendritic arm.Theγ+γ′eutectic structure is mostly distributed in a“sunflower”shape,and the size of the eutectic structure gradually decreases with the increase of withdrawal rate.The morphology of carbides changes from small block like and strip like to skeleton like with the growth height increases.As the withdrawal rate increases,the skeleton like carbides gradually decrease,while the proportion of block like and strip like carbides gradually increases,with smaller sizes and dispersed distributions.

关 键 词：高温合金 定向凝固 微观组织 竞争生长 

分 类 号：TG132.3[一般工业技术—材料科学与工程]