大规格TC4钛合金厚板研制

采用经三次真空自耗电弧熔炼、多向锻造得到的TC4钛合金板坯为原料,以热模拟试验所获得的热加工图为参考,利用西部钛业有限责任公司2 800 mm四辊热轧机成功制备出了宽度为2 300 mm,厚度达到40~70 mm的大规格TC4钛合金厚板,研究了热轧工艺对其组织和室温力学性能的影响。结果表明,轧制温度、道次变形率和应变速率是制备大规格TC4钛合金厚板的关键工艺因素。所制备的TC4钛合金厚板的显微组织为双态组织,由平均晶粒尺寸为25μm的等轴初生α相、拉长的次生α相及晶间β相组成,其室温抗拉强度为925~960 MPa,屈服强度为870~910 MPa,延伸率为12.0%~14.5%。

Research on Preparation of Large-scale TC4 Titanium Alloy Plate

The TC4 titanium alloy plates with width up to 2 300 mm and thickness from 40 to 70 mm have been produced by the 2. 8-meter hot rolling mill at Western Titanium Technologies Co.,Ltd. The starting materials were triple arc-melted and multi-direction forged. And the thermal deformation process parameters were got by the thermal simulation experiment. It was found that heating temperature,reduction of each pass and strain rate are key processing parameters. The optical microstructure reveals that these TC4 titanium alloy plates exhibit duplex microstructure. It is composed of equiaxed primary α grains of about 25 μm size,together with colonies of elongated secondary α grains, and they are surrounded by the intergranularβphase. Mechanical properties tests show that,at the room temperature, the tensile strength of the plate is 925-960 MPa,the yield strength is 870-910 MPa and the elongation is 12. 0% -14. 5%.