The effects of hot compression,hot rolling and post-rolling annealing on microstructure and tensile properties of Ti-6Al-4V were analyzed.Hot compression tests were conducted in the temperature range of 800-1 075 ℃ and at strain rates of 0.001-1 s-1,and the relations between the characteristic points of flow curve and processing variables were developed.Two passes of hot rolling test with total reduction of 75％ were performed in the temperature range of 820-1 070 ℃C and at constant strain rate of 2 s-1.After hot rolling,some specimens were subjected to heat treatment at 870 ℃ and 920 ℃ for 2 h followed by air cooling.Hot rolling in beta phase field resulted in coarse beta grains transforming to martensite by cooling.Otherwise,rolling in the alpha/beta phase filed gave rise to a partially globularized alpha microstructure.The post-rolling heat treatment completed the partial globularization of alpha phase in two-phase region and otherwise broke down the martensitic structure of beta-rolled samples.Tensile tests showed that the strength characteristics as well as elongation decrease significantly with increasing the rolling temperature from the two-phase to the single-phase region.Increasing heat treatment temperature contributed to lower strength for the specimens rolled in two-phase region and higher strength characteristics for the beta-rolled specimens.%研究了热压缩、热轧制和后续轧制退火处理对Ti-6Al-4V合金显微组织和拉伸性能的影响.热压缩实验在温度800～1 075℃和应变速率0.001～1 S-1下进行,得到了流变曲线与加工过程参数之间的关系.然后,样品在温度800～1 070℃和恒应变速率2 S-1下进行2道次热轧制,总变形量为75％.热轧后,样品分别在870℃和920℃下保温热处理2h,随后空冷.在β相区的热轧导致粗大的β相冷却时转变为马氏体相,而在α/β两相区的热轧会导致生成部分球化的α相组织.后续的热轧处理能使在两相区部分球化的α相得以完成球化,然而,在β相区轧制的样品会导致马氏体结构被破坏.拉伸实验表明,随着轧制温度从两相区升高到单相区,合金的强度及伸长率会显著降低.升高热处理温度会降低两相区轧制合金的强度性能,而在β相区轧制合金的强度会得到提高.
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