热轧工艺和退火温度对Ti70板材力学性能及各向异性的影响

Effects of hot rolling process and annealing temperature on mechanical properties and anisotropy of Ti70 sheet

结合性能测试以及OM、SEM、EBSD分析结果,研究了热轧工艺和退火温度对Ti70板材力学性能和各向异性的影响规律及机理。结果表明:轧制工艺对板材力学性能和各向异性具有显著影响,与轧制温度在β相变点附近的传统轧制工艺相比,超低温大变形量的创新轧制工艺的综合力学性能较高且各向异性得到改善。在600~690℃范围内退火,随着温度的升高,强度和冲击功随之降低,而伸长率随之增加,但其对各向异性的改善不明显;同时发现经630℃退火后,板材性能满足船舶在海上运行时的使用要求。创新轧制工艺使得α相由传统工艺的粗片状(间距约6μm)转变为细小纤维状(间距约2μm),通过组织纤维化提高性能;同时创新工艺的交叉换向轧制能够改善板材各向异性。

The effects of rolling process and annealing temperature on the mechanical properties and anisotropy of Ti70 sheets were studied by means of OM,SEM and EBSD.The results show that rolling processes have significant effect on the mechanical properties and anisotropy of the sheets.Compared with the traditional rolling process at the rolling temperature near theβphase transition point,the innovative rolling process with ultra-low temperature and large deformation has higher comprehensive mechanical properties and improved anisotropy.In the range of 600−690℃,with the increase of annealing temperature,the strength and impact energy decrease,but the elongation increases,and the improvement of anisotropy is not obvious.At the same time,it is found that the properties meet the requirements of the ship operating on the sea after sheet annealing at 630℃.The innovative rolling process makes theαphase change from coarse flake(with spacing of about 6μm)to fine fiber(with spacing of about 2μm),and improves the properties through tissue fibrosis;and the cross reversing rolling of the innovative process can improve the anisotropy of plate.