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›› 2019, Vol. 41 ›› Issue (3): 346-353.doi: 10.19562/j.chinasae.qcgc.2019.03.016

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A Study on AHSS Die Life Based on Dynamic Friction and Wear Coefficients

Nie Xin & Wang Chenglong   

  1. Hunan University, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Changsha 410082
  • Received:2018-01-02 Online:2019-03-25 Published:2019-03-25

Abstract: In order to more accurately calculate the wear of advanced high-strength steel (AHSS) stamping die, predict die life, and reveal the effects of constantly changing nodes' pressure and relative sliding velocity during stamping on friction coefficient and wear coefficient, orthogonal experiments on friction and wear are carried out under different pressures and velocities, with corresponding friction coefficient and wear coefficient obtained. Then curve fitting is conducted with pressure and velocity as independent variables and friction coefficient and wear coefficient as dependent variables and a calculation model for dynamic friction coefficient and wear coefficient is put forward. Due to the hardness of plating layer on die surface is changed with its thickness,the coupled die face wear equations for the changing hardness and wear coefficient of die face are established based on experiments and theoretical derivation, a numerical simulation on stamping process is performed by using the model for dynamically changing friction coefficient in stead of Coulomb friction model, and die wear is calculated using coupled die face wear equations, whose results are compared with the scanning data of worn die face. The results show that compared with traditional calculation using constant friction and wear coefficients, the accuracy of wear results calculated by the method proposed is 15.05% higher, and the life prediction on an AHSS drawing die using this method indicates that after 59,000 parts are stamped, the plating layer on some areas of die face is seriously worn and need repair

Key words: die wear, friction coefficient, wear coefficient, die life