The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behav...The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behavior of a flat-rolled wire and to determine the optimal working conditions with materials.The deformation behaviors of wires with various n values were systematically compared using finite element method.The shape of the deformed wire was found to depend on the n value of the material.Both the contact width and lateral spreading of the wire decrease with increasing n,resulting in a large reduction in area with the n value.The strain homogeneity of the wire increases with the n value of the wire.The improvement in the strain homogeneity with the n value is attributable to two factors:a lower strain concentration in the central region and a higher overall elongation as n increases.In addition,the average effective strain of the wire cross section decreases with the n value of a material during wire flat rolling.The contact pressure distribution on the surface of the wire differs significantly depending on the n value.In materials with a low n value,the contact pressure exhibits a higher value at the entry and edge zones of the contact surface.By contrast,materials with high n values exhibit a higher contact pressure at the exit zone.This behavior can be explained by the strain hardening behavior of the material during wire flat rolling.展开更多
The titanium round wires could be prepared to the high precision flat wires with the sizes of 0.63mm×5.03mm by nine-pass cold continuous rolling process.Mechanical property and metallograph analysis were used to ...The titanium round wires could be prepared to the high precision flat wires with the sizes of 0.63mm×5.03mm by nine-pass cold continuous rolling process.Mechanical property and metallograph analysis were used to analyze the possibilities of preparing flat wire.Results show that the grain kept equiaxed grain in the rolling processes,and a large number of dislocation and a small amount of twin existed in the microstructure of final rolling flat wire.During the whole rolling processes,when the accumulated rolling deformation degree was at low degree,the deformation of titanium was controlled under the mutual control of dislocation slip and twinning.When the accumulated rolling deformation degree was at high degree,the deformation of titanium was controlled by the dislocation slip.展开更多
基金This work was partially supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT,South Korea)(No.2021R1A2C1011700).
文摘The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behavior of a flat-rolled wire and to determine the optimal working conditions with materials.The deformation behaviors of wires with various n values were systematically compared using finite element method.The shape of the deformed wire was found to depend on the n value of the material.Both the contact width and lateral spreading of the wire decrease with increasing n,resulting in a large reduction in area with the n value.The strain homogeneity of the wire increases with the n value of the wire.The improvement in the strain homogeneity with the n value is attributable to two factors:a lower strain concentration in the central region and a higher overall elongation as n increases.In addition,the average effective strain of the wire cross section decreases with the n value of a material during wire flat rolling.The contact pressure distribution on the surface of the wire differs significantly depending on the n value.In materials with a low n value,the contact pressure exhibits a higher value at the entry and edge zones of the contact surface.By contrast,materials with high n values exhibit a higher contact pressure at the exit zone.This behavior can be explained by the strain hardening behavior of the material during wire flat rolling.
文摘The titanium round wires could be prepared to the high precision flat wires with the sizes of 0.63mm×5.03mm by nine-pass cold continuous rolling process.Mechanical property and metallograph analysis were used to analyze the possibilities of preparing flat wire.Results show that the grain kept equiaxed grain in the rolling processes,and a large number of dislocation and a small amount of twin existed in the microstructure of final rolling flat wire.During the whole rolling processes,when the accumulated rolling deformation degree was at low degree,the deformation of titanium was controlled under the mutual control of dislocation slip and twinning.When the accumulated rolling deformation degree was at high degree,the deformation of titanium was controlled by the dislocation slip.
