摘要
采用电子背散射衍射(EBSD)技术研究了拉拔过程中珠光体钢丝心部织构演变规律.结果表明,经过多道次干拉和淬火处理的钢丝存在强度较小的<110>丝织构,经过湿拉拔后,<110>丝织构强度明显增加.应用黏塑性自洽模型(VPSC),建立了拉拔过程中钢丝心部织构计算模型,预测了织构的演化规律,并用虚拟的单向拉伸实验研究了初始织构对力学行为的影响.预测结果与EBSD测试结果相符,随着拉拔应变的增加,晶粒的<110>取向逐渐转向拉拔方向.在拉拔方向上的反极图中,存在<113>和<012>连线上稳定的取向,靠近<001>和<111>连线上的取向先转向到稳定取向再转向<110>取向,其它取向直接转向<110>取向.随着拉拔应变增加<110>丝织构的体积分数逐渐增加,增加速率逐渐减小.随着初始<110>丝织构体积分数的增加钢丝心部的屈服应力逐渐增加.
The cold drawing pearlitic steel wires are widely used in industry such as the automobile tire and ropes. And it possesses an ultra high strength, almost the highest in all the steel products. So many investigations are focused on the hardening mechanisms of pearlitic steel wire during cold drawing, including the microstructure fining, texture evolution and cementite dissolution. In this study, the electron backscatter diffraction（EBSD） and the visco-plastic self-consistent（VPSC） model are used to investigate the texture evolution law at the center of wire during the drawing, as well as its influences on the mechanical behaviors. The EBSD results show that the asreceived wires after dry drawing and quenching have a little 110 fiber texture along the drawing direction. And with wet drawing strain increasing, the intense of 110 fiber texture increases apparently. The calculations using VPSC have a good agreement with the EBSD results, which indicate that VPSC can successfully predict the texture category and its evolution law in pearlitic steel wire during drawing. The predictions show that the 110 fiber texture is gradually generated at the center of wire with strain increasing and exhibit the path of individual orientation in the inverse pole figures during the drawing. The orientations at the line linking 113 and 012 seem stable. The orientations located at the line linking 001 and 111 prefer to turn to the stable orientations and then turn to 110. The other orientations turn to 110 directly. The volume of 110 orientations within 15 degrees of drawing direction increases with strain increasing and get saturation finally. The tensile yield stress of the wire center increases with the initial volume of 110 fiber texture increasing.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第6期667-673,共7页
Acta Metallurgica Sinica
基金
贝卡尔特(亚洲)研发中心合作项目
国家自然科学基金项目51034009
广东省中国科学院全面战略合作项目2012B091100251资助~~
关键词
珠光体钢丝
晶体学织构
黏塑性自洽模型
力学性能
pearlitic steel wire
crystallographic texture
visco-plastic self-consistent model
mechanical property
