海洋环境下钛合金主要服役性能研究

Service Performance of Titanium Alloy in Marine Environment

随着我国海洋装备对高性能材料的需求越来越紧迫,具有高比强度和优异耐腐蚀性能的钛合金受到越来越多的重视。然而,由于缺乏海洋环境下钛合金的相关服役性能数据,导致装备设计单位和应用单位选材困难,极大限制了钛合金在我国海洋工程装备上的应用。针对钛合金在海洋环境下服役面临的主要失效形式:压缩蠕变、低周疲劳和应力腐蚀,研究了不同组织形貌对TC4 ELI钛合金相关服役性能的影响,研究结果表明:TC4 ELI钛合金网篮组织的压缩蠕变性能优于双态组织;双态组织的低周疲劳性能优于魏氏组织;魏氏组织的抗应力腐蚀性能优于双态组织。可见,组织形貌对钛合金的服役性能具有重要影响,应根据具体的服役工况进行选取。

Titanium alloys,which possess high specific strength and excellent corrosion resistance,have received more and more attention,due to urgent demands of marine equipments for high-performance materials.However,application of titanium alloys is limited in our marine equipments due to absence of service performance data,our equipment design and application units are hesitated to choose materials type.In the present study,compressure creep,low cycle fatigue and stress corrosion property of TC4 ELI alloy with different microstructures were investigated.Results indicated that the basketweave microstructure possesses better compression creep behavior in comparison with duplex microstructure,the duplex microstructure possesses better low cycle fatigue property in comparison with Widmanstatten microstructure,and the Widmanstatten microstructure possesses better stress corrosion property in comparison with duplex microstructure.It can be seen that the microstructure has important effects on the service performance of titanium alloys,it should be selected according to the specific service conditions.