初始直径和拉拔道次对QCr0.5线材组织和性能的影响  

Effects of Initial Diameter and Drawing Passes on Microstructures and Properties of QCr0.5 Wires

作　　者：王露娟[1,2] 宋克兴[1,2] 张彦敏[1,2] 王青[2,3] 

机构地区：[1]河南科技大学材料科学与工程学院 [2]河南省有色金属材料科学与加工技术重点实验室 [3]西安理工大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2013年第8期778-780,共3页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51075122)

摘　　要：将初始直径为φ7、φ5、φ3mm的QCr0.5线材进行平均应变为0.05和0.1两种不同拉拔道次的冷拉拔,得到不同应变量的试样,测试了试样的硬度和电导率,并进行了微观组织观察,研究了不同初始直径和拉拔道次对QCr0.5线材组织和性能的影响。结果表明,在同一拉拔道次下,不同初始直径线材的电导率随着应变量的增加都呈下降趋势,φ7mm线材下降最多,φ5mm线材次之,φ3mm线材下降最少。在同一初始直径下,不同拉拔道次线材的电导率随着应变量的增加都缓慢降低,硬度先快速上升,后有所下降,最后基本保持不变。平均应变为0.1的拉拔道次比平均应变为0.05时的电导率下降幅度更大,下降约37%,而硬度却始终都更高,最高硬度HV达114。微观组织观察表明,QCr0.5线材横截面组织演化的特点是:内外部组织变形不均匀,外部组织发生变形的程度比内部组织要剧烈。随着变形量的进一步加大,最后内部组织逐渐与外部组织趋于一致。Three QCr0. 5 wires with initial diameters of Ф7 mm, 45 mm and Ф3 mm were cold drawn through different drawing passes with average strains of 0.05 and 0.1, respectively, to obtain the sam- ples with different strain rate. The hardness and electrical conductivity of the samples obtained were measured and the microstructures were observed to understand the effects of initial diameter and drawing passes on microstruetures and properties of QCr0.5 wires. The results show that the electrical conduc- tivity of the cold drawn samples with different initial diameters is decreased with increasing in the strain, where the samples with ~7 mm have the maximum decrement value, the samples with 45 mm are the sec- ond, and samples with ~3 mm have the lowest decrement value. The electrical conductivity of the sam- ples with different drawing passes is decreased slowly with increasing in the strain under the same initial diameter, and the hardness is increased rapidly firstly, and then decreased slowly to a constant tenden- cy. The decrease of electrical conductivity of the samples with average strain of 0.1 is more rapid than that one with the average strain of 0.05, and it is decreased by approximately 37 %, however, the hard- ness is always the higher, where the highest hardness can reach to 114 HV. The microstructure obser- vation reveals that the microstrueture evolution of QCr0.5 is characterized by the uneven deformation of the internal and external structure, and the deformation degree of the external structure exhibits more severe. With the deformation increase, the deformation of internal and external structure tends to be homogeneous.

关 键 词：QCr0 5线材 应变量 初始直径 拉拔道次 电导率 硬度 微观组织 

分 类 号：TG356.4[金属学及工艺—金属压力加工]