TA19钛合金大规格棒材的组织和性能研究

Study on Microstructure and Properties of TA19 Large Size Titanium Alloy Bar

通过选择合理的锻造工艺对规格为准200 mm/准250 mm伊长度逸2000 mm的TA19钛合金大规格棒材进行了研究,并分析测试了棒材的组织和性能。结果表明通过茁相区和近茁相区多火次反复的镦拔,提高了TA19棒材组织均匀性,细化了晶粒;在α＋茁相区采用较高温度（低于茁相变点30℃）锻造成形,获得了初生α比例（20%-25%）较佳的双态组织,得到了综合性能良好的大规格棒材。TA19两种规格的成品棒材室温和高温抗拉强度分别为1050、700MPa,屈服强度分别为950、560 MPa,均高出标准约15%,且伸长率、高温持久和高温蠕变性能均满足协议标准要求。

Large-size TA19 titanium alloy bars with φ200mm/φ250mm×length ≥2000mm were studied by selecting the reasonable forging technology. And mierostructure and mechanical properties of the bar material were tested and analyzed. The results indicate that： through multiple fires iterative upsetting and stretching swaging in β phase region and near 13 phase region, microstrueture uniformity of TA 19 bar is increased, and the grains are refined; better duplex microstructure of primary α ratio （20% - 25%） is obtained by using high temperature （below β phase variable points 30 ℃） forging forming in α＋β phase region, and large-size bar materials of good comprehensive properties are gotten. The room temperature and high temperature tensile strength of TA19 finished bars with two specifications are 1050 and 700 MPa respectively, and the yield strengths are 950 and 560 MPa respectively, which are higher about 15% than standard. And elongation, high temperature endurance and high temperature creep properties meet the agreement standard requirements.