(1. 沈阳工业大学 材料科学与工程学院，沈阳 110178;
2. 东北大学 轧制技术及连轧自动化国家重点实验室，沈阳 110004)
摘 要: 采用热处理、蠕变性能测试及位错组态的衍衬分析，研究热连轧Ti-6Al-4V合金的蠕变行为及影响因素。结果表明：经低于β相变点的固溶处理，合金的组织结构由高固溶度的等轴α相和网篮组织组成；随着固溶温度提高，网篮组织数量增多；经1 000 ℃固溶处理后合金可获得完全网篮组织；与940 ℃固溶时效合金相比，经 1 000 ℃固溶时效合金在420 ℃、575 MPa条件下具有较低的应变速率和较长的蠕变寿命；在试验的温度和应力范围内，计算出该合金的蠕变激活能为249.8 kJ/mol；在蠕变期间，热连轧合金的变形机制是位错在具HCP结构的α相中发生双取向滑移，940 ℃固溶处理合金的蠕变机制是波浪状áa+cñ位错在α相中发生锥面滑移，而经1 000 ℃固溶处理合金的变形机制是(1/2)á111ñ位错在具BCC结构的β相中发生多系滑移；经1 000 ℃固溶处理合金中所含的高含量富V的β相可提高合金蠕变抗力，这是合金具有较低应变速率和较长蠕变寿命的主要原因。
关键字: Ti-6Al-4V合金；热连轧；固溶处理；蠕变；变形机制
hot continuous rolled Ti-6Al-4V alloy
（1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110178, China;
2. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, China）
Abstract:By heat treatment, measurement of creep properties and contract analysis of dislocations configuration, the creep behaviors and the effect factors of hot continuous rolled (HCR) Ti-6Al-4V alloy were investigated. The results show that, after the alloy solution treated at temperatures lower than β phase transformation point, the microstructures of the alloy consist of the supersaturation equiaxial α phase and network basket structure. The quantities of the network basket structure increase as the solution temperature increases, and the full network basket structure may be obtained after solution-treated at 1 000 ℃. Compared with the alloy solution treated at 940 ℃, the alloy solution treated at 1 000 ℃ displays a lower strain rate and a longer creep lifetime under the conditions of the applied stress of 575 MPa at 420 ℃. In the range of the applied temperatures and stresses, the creep activation energy of the alloy is calculated to be 249.8 kJ/mol. The deformed mechanism of HCR alloy during creep is double orientation slipping of dislocations activated within α phase with HCP structure, while the deformed feature of the alloy solution treated at 940 ℃ is the wave-like áa+cñ dislocations activated on the pyramidal planes in α phase. After solution treated at 1 000 ℃, the deformed mechanism of the alloy is the multiple slipping of (1/2) á111ñ dislocations activated within β phase with BCC structure. In this alloy, the high volume fraction V-riched β phase may enhance the creep resistance of the alloy. This is the main reason why this alloy possesses relatively low strain rate and long creep lifetime.
Key words: Ti-6Al-4V alloy; hot continuous rolling; solution treatment; creep; deformation mechanism
