Jixie qiangdu (Jan 2022)
RESEARCH ON BENDING FORMABILITY OF Q960 STRUCTURAL STEEL PLATE ASSISTED BY PULSE CURRENT
Abstract
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 13 μm 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.
