大规格Ti70合金铸锭Fe元素偏析控制

Fe Elemental Segregation Control of Large Size Ti70 Alloy Ingot

摘要:

本文使用真空自耗熔炼(VAR)法对Ti70大规格铸锭进行了制备,研究了熔炼速度对易偏析Fe元素成分均匀性的影响。文中使用化学法测试了铸锭的化学成分并与前期试制结果进行对比,使用电子能谱仪对铸锭微区成分进行扫描,使用金相显微镜观察了后续轧制板材的显微组织,并用拉伸试验仪检测了板材的力学性能。结果表明：通过控制熔速保持相对恒定,可有效减少铸锭凝固时固-液共存区宽度,降低Fe元素宏观偏析；同时降低熔速可使共晶相片间距变窄,减轻Fe元素微观偏析趋势。对所制备的铸锭进行后续锻造及板材轧制,其组织性能符合标准要求。

Abstract:

Large size Ti70 alloy ingot were manufactured by vacuum consumable arc melting(VAR) in this paper. The effect of melting rate on component homogeneity of Fe element was studied. Chemical composition of the ingots were measured by chemical composition analyser and compared with perp results. Micro area composition were detected with EDS. Microstructure of follow-up rolling plate was observed by a metalloscope and mechanical properties of the plate were tested by a tensile tester. The results show that the mush zone during solidification process of the ingot reducing and macrosegregation of Fe element decreasing with cutting down the melting rate to a stable level. Meanwhile, eutectic phase spacing narrowing down and microsegregation of Fe element alleviating with reducing the melting rate. The microstructure and tensile properties of the follow-up rolling plate compliancing with the standard requirements.