(1. 北京航空材料研究院,北京 100095;2. 沈阳飞机设计研究所,沈阳 110035)
摘 要: 研究MJ5和MJ6 两种规格的BT16钛合金沉头螺栓显微组织、流线和显微硬度,并与直径为6 mm的该合金丝材的显微硬度和组织进行对比。研究结果表明:BT16钛合金螺栓光杆部位显微硬度与直径为6 mm的丝材退火状态下的硬度相当;螺杆部位经受冷挤压缩径和螺纹滚制双重冷变形强化,显微硬度明显高于光杆部位的显微硬度;螺栓显微组织与丝材退火状态下的显微组织一致,进一步证实螺栓是在退火状态下直接使用的,未经过热处理强化,BT16钛合金沉头螺栓采用一次缩径的冷变形强化制造工艺。
关键字: BT16钛合金;紧固件;显微组织
(1. Beijing Institute of Aeronautical Materials,Beijng100095, China;
2. Shenyang Institute of Aircraft Design, Shenyang 110035, China)
Abstract:The microstructure, streamline and microhardness of two different sizes BT16 countersunk head bolts were analyzed, and compared with that of thread of BT16 titanium alloy with diameter of 6 mm. The results show that the micro hardness of shank is similar to that of as-annealing thread with diameter of 6 mm. The micro hardness of screw is obviously higher than that of the shank because of cold deforming strengthen. Microstructure of BT16 bolt is very similar to that of thread in annealing state, which shows that the bolt can be used in annealing state without solution treatment and aging. Streamline and hardness analyses results show that BT16 countersunk head bolts are deformed under cold condition.
Key words: BT16 titanium alloy; fastener; microstructure