浮动凹模热精密成形圆柱斜齿轮微观组织演化规律的研究

Research on Microstructure Evolution Rules of Helical Gears by Hot Precision Forming with Floating Die

利用有限元软件Deform建立了圆柱斜齿轮浮动凹模热成形-传热-微观组织耦合有限元模型,模拟了浮动凹模工艺中不同凸、凹模速度下齿轮热成形过程,研究了不同浮动凹模速度和凸模压下速度对斜齿轮微观组织演化的影响规律。结果表明,在相同运动模式下,随着上凸模下压速度增大,成形齿轮发生动态再结晶的区域和晶粒细化区域逐渐由齿根向齿面扩展,并随着上凸模下压速度增大,动态再结晶体积分数平均值越大,平均晶粒尺寸越小。

The finite element model of hot forming with floating die-heat transfer-microstructure coupling of the cylindrical helical gear was established by using finite element software Deform.The hot forming process of the gear with different upper die and lower die speeds in floating die process was simulated.The influence of different floating die velocity and upper die velocity on the microstructure evolution of the helical gear was studied.The results show that the dynamic recrystallization region and grain refinement region of the forming gear gradually expand from the tooth root to the tooth surface with the increase of the pressing speed of the upper die under same motion mode.With the increase of pressing speed,the average volume fraction of dynamic recrystallization increases and the average grain size becomes smaller.