差温无模预成形锻造的有限元模拟研究

FE simulating study on thermal differential mouldless preform forging

利用热力耦合有限元方法 ,对AISI10 4 5钢圆柱体坯料在环形加热源局部加热下的差温无模预成形锻造过程进行了模拟研究。模拟结果表明 ,在坯料中获得和控制大梯度分布的不均匀温度场是实现无模预成形锻造的关键。复杂零件成形必须合理地组合加热源和冷却源 ,以便产生所需的温度梯度场。在快速变形条件下 ,变形过程中的持续加热对金属的流动影响甚微 ,变形前的温度分布基本上决定了金属的流动 ,但在慢速变形条件下 ,变形过程中的持续加热对金属的流动产生一定的影响 ,其影响程度视零件复杂程度而异。从该文研究结果可以预见 。

The simulating study for the thermal differential mouldless preform forging of AISI1045 steel cylindrical billet subjected to local ring heat sources was performed by coupled thermal\|viscoplastic FEM.The results showed that obtaining and controlling large temperature gradients within billet are the keys for mouldless preform forging.In order to produce the expected temperature distributions for forging of complex geometries,heating and cooling sources must be appropriately combined.The metal flow in fast forging is basically controlled by the temperature distributions prior to deformation and is affected very slightly by the continuously in\|situ heating during deformation.However,the metal flow in slow forging is,affected by the continuously in\|situ heating during deformation,which is related to complex extent of component.Based on the results of the presented study,it can be predicted that the thermal differential mouldless forging can be developed as a new process of the mouldless making billet.