大尺寸优质GH4738合金铸锭的元素偏析规律及均匀化工艺  

Element segregation and homogenization process of large size and high quality GH4738 alloy ingot

作　　者：马亚芬 李育升 张麦仓[1] 杨成斌 荣义 侯为学 曲敬龙 MA Ya-fen;LI Yu-sheng;ZHANG Mai-cang;YANG Cheng-bin;RONG Yi;HOU Wei-xue;QU Jing-long(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Cisri-gaona Aero Materials Co Ltd,Beijing 100081,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]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》2023年第6期81-89,共9页Transactions of Materials and Heat Treatment

基　　金：科技部重大专项(2021YFB3700403);国家自然科学基金(51971016)。

摘　　要：利用光学显微镜、扫描电镜及电子探针分析了大尺寸优质GH4738合金铸锭的铸态组织及凝固偏析特性,研究了不同均匀化工艺对优质GH4738合金微观组织、析出相和元素偏析情况的影响,并通过Gleeble-1500热模拟试验机的热压缩试验验证了均匀化处理工艺的合理性。结果表明:优质GH4738合金铸锭枝晶发达,存在明显元素偏析,Ti元素偏聚于枝晶间,偏析程度最严重。经1160℃×24 h+1190℃×72 h均匀化处理后,铸锭不同部位的偏析元素扩散均匀,中心处共晶相与低熔点相完全回溶,试验结果与利用残余偏析指数δ的理论计算结果吻合良好。均匀化后的合金在Gleeble热模拟压缩试验后表现出了良好的变形塑性。As-cast microstructure and solidification segregation characteristics of large size and high quality GH4738 alloy ingots were analyzed by means of optical microscope,scanning electron microscopy and electron probe.The effects of different homogenization processes on the microstructure,precipitates and element segregation of the high quality GH4738 alloy were studied.The rationality of homogenization process was verified by the thermal compression test of Gleeble-1500 thermal simulator.The results show that the highquality GH4738 alloy ingots have well-developed dendrites and obvious element segregation,and the Ti element is concentrated between dendrites,with the most serious segregation degree.After homogenization treatment at 1160℃for 24 h and at 1190℃for 72 h,the segregation elements in different areas of the ingot diffuse uniformly,the eutectic phase and low melting point phase at the center are completely dissolved,and the experimental results are in good agreement with the theoretical calculations using the residual segregation index ofδ.The homogenized alloy shows good deformation plasticity after Gleeble thermal simulation compression test.

关 键 词：优质GH4738合金 元素偏析 均匀化处理 

分 类 号：TG132.3[一般工业技术—材料科学与工程]