喷射成形2195铝锂合金封头旋压及焊接试验研究

Spinning and Welding Test Investigation of Shell Cover of Spray-Formed 2195 Al-Li Alloy

采用喷射成形2195铝锂合金板材进行了封头部件的旋压,通过应力检测、力学性能试验以及电子背散射衍射(EBSD)等方法对旋压后材料的组织和性能进行了分析,采用两件旋压封头零件完成了φ400 mm直径箱体焊接及强度试验验证,获得了对该种材料旋压、焊接成形工艺与其组织性能相关性的基本认识.试验结果表明,喷射成形2195铝锂合金采用适当的旋压+热处理工艺能够整体制备出封头类回转体零件,旋压件经固溶+时效处理后抗拉强度可达470~495 MPa,延伸率可达5%~6%.旋压过程中在材料表面会产生明显的冷作硬化作用,需进行中间退火处理,以消除表面硬化、降低残余应力.旋压后材料的组织状态呈现由旋压产生的层状结构,且以细小的晶粒带状为特征,其晶粒尺寸及分布可作为旋压工艺效果的评价依据.焊后采用0.52 MPa的设计压力对箱体容器进行了强度试验考核,验证了箱体焊缝能够达到同类容器的强韧性要求.

In this study,to analyze the microstructure and properties of a shell cover produced by spinning it along with a spray-formed 2195 Al-Li alloy plate,we conducted a stress test,a mechanical properties test,and performed electron backscatter diffraction.A tank with a diameter of 400 mm was welded from two shell covers and its strength was verified by hydrostatic testing.The basic relations among the spinning process,welding parameters,microstructure,and properties were satisfactorily determined.The test results showed that some helicoid components can be produced from spray-formed 2195 Al-Li alloy by selecting the proper spinning and heat treatment parameters in combined processes.This result verifies the feasibility of the applied processes and corresponding parameters.The strength of the spin-formed sample component reached 470-495 MPa with an elongation percentage of 5%-6%after solution and aging treatments.In the spinning process,since cold-work hardening effects occur on the surface of the material,an intermediate annealing treatment is required to mitigate surface hardening and reduce residual stress.The spinning components have a typical stratified microstructure with a fine grain band,and the gain size and its distribution can be used as a criterion for the spinning process.After spinning,the material was found to maintain good welding performance,and the strength and toughness of the welding joint can be ensured by the use of an optimized welding process.The results of the hydrostatic strength test of the tank were successful at an applied pressure of 0.52 MPa,which indicates that the produced tank met the strength and toughness requirements of similar container components.