摘要
为了提高建筑用Q960结构钢板的弯曲成形性能,通过脉冲电流辅助方式对其内部组织进行增强。测定了Q960结构钢板受到脉冲电流作用时弯曲回弹性差异,对合金施加不同脉冲电流密度进行弯曲测试,并观察其组织形貌的变化。研究结果表明:对Q960钢板进行90°V型弯曲测试得到的中性层偏移系数都达到了0.5以上。当电流密度增大后,试样从弹性变形过渡到塑性变形,试样温度发生了持续升高。对试样施加电辅助处理时,增大电流密度后,发生了弯曲回弹角的降低;当电流密度达到2.5 A/mm时,已经观察不到回弹现象。在弯曲阶段加入脉冲电流时,逐渐提高电流密度后合金组织结构形成更少孪晶。外侧形成了大量等轴晶组织,呈现滑移塑性变形特征,引起了轻微的不对称拉压状态。晶粒大小约为13μm,电塑性作用引起基面组织发生滑移,使得材料无需经过孪晶协调的过程便能够完成塑性转变。该研究对提高建筑结构钢的力学性能具有很好的意义,尤其适用于高层建筑。
To improve the bending formability of Q960 structural steel plate,the internal structure of the steel plate was enhanced by pulse current assisted method.The bending resilience difference of Q960 structural steel plate was measured when it is subjected to pulse current.The alloy was subjected to different pulse current densities for bending test,and the change of microstructure morphology was observed.Results show that the deviation coefficients of neutral layer are above 0.5 after 90°V bending test.When the current density increases,the specimen changes from elastic deformation to plastic deformation,and the temperature of the specimen increases continuously.When electrically assisted treatment is applied to the sample,the bending rebound Angle decreases with the increase of current density.When the current density reaches 2.5 A/mm~2,no rebound phenomenon can be observed.Few twin crystals will appear with gradual increase of the current density in the bending process.A large number of equiaxed crystal structures are formed on the outer side,showing the characteristics of slip plastic deformation,resulting in a slightly asymmetric tension and compression state.With a grain size of 13μm or so,the microstructure of the base plane slips due to electroplastic action,which realizes the plastic transformation of the material without twin coordination.The research is of great significance to improve the mechanical properties of building structural steel,especially for high-rise buildings.
作者
马楠
王素英
王琳
李迎乐
MA Nan;WANG SuYing;WANG Lin;LI YingLe(School of Civil Engineering and Architecture,Zhengzhou University of Economics and Trade,Zhengzhou 451191,China;School of Architecture and Design,Southwest Jiaotong University,Chengdu 611756,China;Huashe Design Group Co.,Ltd.,Nanjing 210000,China)
出处
《机械强度》
CAS
CSCD
北大核心
2022年第4期991-995,共5页
Journal of Mechanical Strength
基金
河南省高等学校重点科研项目(20A480006)
河南省科技发展计划项目(202102310556)资助。
关键词
脉冲电流辅助
Q960钢板
弯曲成形
微观组织
回弹
孪晶
塑性变形
Pulse current assist
Q960 steel plate
Bending forming
Microstructure
Springback
Twin
Plastic deformation
