后处理对退火态Ti75合金组织与性能的影响  

Effect of post heat treatment on the microstructure and properties of as-annealed Ti75 alloy

作　　者：尹艳超 李龙腾 吕逸帆 孙志杰 余巍 蒋鹏 Yin Yanchao;Li Longteng;LüYifan;Sun Zhijie;Yu Wei;Jiang Peng(Luoyang Ship Material Research Institute,Luoyang 471023,Henan,China)

机构地区：[1]中国船舶集团有限公司第七二五研究所,河南洛阳471023

出　　处：《钢铁钒钛》2023年第5期68-75,共8页Iron Steel Vanadium Titanium

基　　金：郑洛新自创区产业集群专项(201200211400)。

摘　　要：为了研究后处理对退火态Ti75合金性能的影响,采用不同后处理温度和冷却速率对退火态Ti75合金进行处理,利用OM、SEM分析了显微组织演变,并研究了显微组织对拉伸、冲击性能的影响。结果表明,后处理温度较低时,等轴α相的体积分数无明显变化;当温度升至足够高时,等轴α相开始溶解,其体积分数随着温度的升高逐渐降低。退火态Ti75合金经750~950℃处理后空冷的强度、冲击韧性变化趋势与炉冷基本相同。屈服强度、抗拉强度随后处理温度的升高呈现先降低后升高又降低的趋势,强度升高的主要原因是β转变组织中数量较多的细小α相难以变形;冲击韧性在低温区无明显变化,而后随温度的升高而逐渐升高。退火态Ti75合金经相同温度处理后空冷的强度高于炉冷;在低温区,空冷后的冲击韧性高于炉冷,高温区则呈现相反的规律。In order to study the effect of post heat treatment on the properties of annealed Ti75 alloy,different post treatment conditions including annealing temperatures and cooling rates were selected to treat the annealed Ti75 alloy.The microstructure evolution was analyzed by OM and SEM,and the influence of microstructure on tensile properties and impact toughness of Ti75 alloy was studied.The results show that the volume fraction of equiaxedαphase has no obvious change when alloy is annealed at low temperature.When the annealing temperature is high enough,the equiaxedαphase begins to dissolve and its volume fraction decreases gradually with the increase of temperature.The evolution of strength and impact toughness of annealed Ti75 alloy after air cooling by different annealing temperature at 750-950℃is basically the same as that of furnace cooling.The yield strength and tensile strength decrease firstly,then increase a little and then decrease again with the increase of temperature.The main reason for strength increasing is that a large number of fineαphases exists in theβtransformation matrix structure which are difficult to deform.The impact toughness has no obvious change when alloy is annealed at low temperature region and then increases with the increase of temperature.The strength of annealed Ti75 alloy after annealing and air cooling is higher than that of furnace cooling.The impact toughness of annealed Ti75 alloy after annealing at low temperature region and air cooling is higher than that of furnace cooling,while at the high temperature region it shows the opposite changing tendency.

关 键 词：退火态Ti75合金 后处理 显微组织 强度 冲击韧性 

分 类 号：TF823[冶金工程—有色金属冶金] TG146.2[一般工业技术—材料科学与工程]