关键词: 弹性模量, 非弹性回复, 回弹仿真, 相变诱发塑性

Abstract: Inelastic recovery behavior introduced by plastic deformation is analyzed for transformation-induced plasticity steels. By uniaxial tension testing of transformation-induced plasticity steels under different strain levels, microstructures before and after deformation are detected by scanning electron microscope. The mechanism of inelastic recovery is analyzed with the dislocation theory. The emphasis is put on the composition of the inelastic strain recovery of transformation-induced plasticity (TRIP) steel during unloading and its variation regulation with the plastic strain. An elastic modulus model is built through the fitting of test data. Then the model is introduced into finite element software to simulate the U-channel springback and lab springback experiments are carried out to verify the simulation precision. It is shown that the transformed martensite introducing the microstructure disturb gives the prominent inelastic recovery to TRIP steels. The total strain recovery is composed by the elastic strain recovery and the inelastic strain recovery, among which the percentage of the inelastic strain recovery can reach 20%. The springback simulation result calculated by the proposed elastic modulus model is consistent with the experimental result.

Key words: Elastic modulus, Inelastic recovery, Springback simulation, Transformation-induced plasticity (TRIP)