【作者】 陈军； 王廷询； 杨海瑛； 杜宇； Yang Yingli； Zhou Wei； Li Qian； Xin Shewei； Zhao Liang；

【Author】 Chen Jun;Wang Tinxun;Du Yu;Yang Yingli;Yang Haiying;Zhou Wei;Li Qian;Xin Shewei;Zhao Liang;Northwest Institute for Nonferrous Metal Research;

【机构】 西北有色金属研究院；

【摘要】 本文研究Ti75钛合金弯头在扩径推弯短半径弯头过程中的变形特性和组织性能演化规律。研究结果表明:扩径推弯短半径弯头是一种轴向压缩弯曲变形、径向偏心扩径变形的过程,腹部压缩变形量大于背部,在偏心扩径过程中,腹部弯曲压缩变形增厚部分由腹部沿弯头两侧向背部发生金属流变,弥补减薄的背部金属,以保证弯头壁厚均匀性。壁厚均匀性与羊角芯头设计、推制温度和温度场、推制速度等因素有关,扩径推弯钛合金短半径弯头是切实可行的。Ti75钛合金在两相区推制,可降低合金变形抗力,提高合金塑性,同时,弯头可保持与管坯相一致的组织和性能;?相区加工容易产生过烧和晶粒过分长大。未退火Ti 75钛合金弯头强度低于退火后的强度,弯头退火后有利于强度的提高和组织均匀化。更多还原

【Abstract】 The deformation feature and evolution regularity of microstructure and properties of Ti 75 titanium alloy with short bending radius made by Expanding-diameter and pushing bend procedure are studied in this paper. The results are shown that the method of elbow with short bending radius made by expanding-diameter and pushing bend is feasibility; it is composed of compressing and bending deformation in axial direction and off-centering expanding diameter in radial direction. The compressing deformation degree of elbow in belly region is larger than that of elbow in back region. The thickening fraction which is result from large compressing deformation in belly region, generates metal rheology from belly region to back region along bilateral of elbow under the restraint of ram-shaping deformation die during off-centering expanding diameter processing. The reducing degree in back of elbow which is result from expanding diameter is make up recover by rheology material to keep uniformity of wall thickness. The wall thickness uniformity is relationship with facts of design of ram-shaping molding die, pushing temperature and temperature field, pushing rate and so on. In order to assure compatibility of microstructure and property between elbow and tube, the elbow deformed in two phase region is assured to reduce resistance of deformation and increase plasticity. The burnt structure and overlarge grain size easily is take place in ? phase region. The property of elbow without annealing is lower than that of elbow after annealing in two phase region, so annealing is of advantage to increasing tensile strength and microstructure uniformity.更多还原