In order to decrease the anisotropy of mechanical properties, the rigid-plastic mechanical model for the forging method with horizontal V-shaped anvil is presented. The forging method, through the change of anvils sha...In order to decrease the anisotropy of mechanical properties, the rigid-plastic mechanical model for the forging method with horizontal V-shaped anvil is presented. The forging method, through the change of anvils shape, is able to control fibrous tissue direction, to improve the anisotropy of mechanical properties of axial forgings, to realize uniform forging. Therefore, the forging method can overcome the defect that conventional forging methods produce. The mechanism of the forging method with horizontal V-shaped anvil and the process of metal deformation are analyzed. The agreement of theoretical analysis with experimental study verifies the fact that the forging method with horizontal V-shaped anvil can control effectively the mechanical properties of axial forgings.展开更多
低压转子是核电机组关键零部件。低压转子锻件方截面坯料倒棱工艺一般采用普通平砧或无曼内斯曼效应的锻造法(Free from Mannesmann effect,FM)法,锻坯的变形仅集中在表层,难以深入心部,这浪费了倒棱工艺的大压下量。提出一种新的改进...低压转子是核电机组关键零部件。低压转子锻件方截面坯料倒棱工艺一般采用普通平砧或无曼内斯曼效应的锻造法(Free from Mannesmann effect,FM)法,锻坯的变形仅集中在表层,难以深入心部,这浪费了倒棱工艺的大压下量。提出一种新的改进工艺方案,采用V形砧倒棱工艺来改善锻件心部应力应变状态,并通过数值模拟和物理模拟相结合的方法对其应力应变的分布进行研究。模拟结果表明,采用V形砧倒棱工艺,锻件心部等效应变增加,静水压力增大,随V形砧角度的减小应力应变分布效果更好;本质为型砧侧壁和锻件的接触面积的增加,使得接触处形成难变形区,从而使锻件取得更好的心部应力应变条件。连砧倒棱在两砧相搭接处对应区域存在小变形区,可以通过错砧工艺进行消除。建议倒棱工艺采用V形砧,角度小于等于120°,压下率大于20%,连砧错砧。展开更多
Computer modelling using an FEM-based program, i.e. Forge 2008, was carried out. Laboratory model-ling of the process of free hot forging in shaped anvils was conducted to close up metallurgical defects. Results ob- t...Computer modelling using an FEM-based program, i.e. Forge 2008, was carried out. Laboratory model-ling of the process of free hot forging in shaped anvils was conducted to close up metallurgical defects. Results ob- tained from the simulation modelling were processed by using a commercial statistical package, i.e. Statistica 6.0 PL. The influence of the anvil shape and main parameters of the forging process on closing up metallurgical defects were determined. On the basis of the investigation carried out, the optimal values of main forging technologieal parameters and suitable groups of anvils to be used in particular forging tages are proposed for the elimination of metallurgical defects.展开更多
基金This project is supported by National Natural Science Foundation of China (No.59235101).
文摘In order to decrease the anisotropy of mechanical properties, the rigid-plastic mechanical model for the forging method with horizontal V-shaped anvil is presented. The forging method, through the change of anvils shape, is able to control fibrous tissue direction, to improve the anisotropy of mechanical properties of axial forgings, to realize uniform forging. Therefore, the forging method can overcome the defect that conventional forging methods produce. The mechanism of the forging method with horizontal V-shaped anvil and the process of metal deformation are analyzed. The agreement of theoretical analysis with experimental study verifies the fact that the forging method with horizontal V-shaped anvil can control effectively the mechanical properties of axial forgings.
文摘低压转子是核电机组关键零部件。低压转子锻件方截面坯料倒棱工艺一般采用普通平砧或无曼内斯曼效应的锻造法(Free from Mannesmann effect,FM)法,锻坯的变形仅集中在表层,难以深入心部,这浪费了倒棱工艺的大压下量。提出一种新的改进工艺方案,采用V形砧倒棱工艺来改善锻件心部应力应变状态,并通过数值模拟和物理模拟相结合的方法对其应力应变的分布进行研究。模拟结果表明,采用V形砧倒棱工艺,锻件心部等效应变增加,静水压力增大,随V形砧角度的减小应力应变分布效果更好;本质为型砧侧壁和锻件的接触面积的增加,使得接触处形成难变形区,从而使锻件取得更好的心部应力应变条件。连砧倒棱在两砧相搭接处对应区域存在小变形区,可以通过错砧工艺进行消除。建议倒棱工艺采用V形砧,角度小于等于120°,压下率大于20%,连砧错砧。
文摘Computer modelling using an FEM-based program, i.e. Forge 2008, was carried out. Laboratory model-ling of the process of free hot forging in shaped anvils was conducted to close up metallurgical defects. Results ob- tained from the simulation modelling were processed by using a commercial statistical package, i.e. Statistica 6.0 PL. The influence of the anvil shape and main parameters of the forging process on closing up metallurgical defects were determined. On the basis of the investigation carried out, the optimal values of main forging technologieal parameters and suitable groups of anvils to be used in particular forging tages are proposed for the elimination of metallurgical defects.
