大型核电低压转子锻件倒棱新工艺的模拟  

Simulation on New Chamfering Process of Nuclear Turbine Low-pressure Rotor Forging

作　　者：刘鑫[1,2] 钟约先[1,2] 马庆贤[1,2] 袁朝龙[1,2] 

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学先进成形制造教育部重点实验室,北京100084

出　　处：《机械工程学报》2010年第24期16-21,共6页Journal of Mechanical Engineering

基　　金：'十一五'国家科技支撑计划(2007BAF02B07;2007BAF02B01);国家自然科学基金(50705048);教育部博士点基金(20070003080)资助项目

摘　　要：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。Low-pressure rotor is a key component of pressurized-water reactor（PWR）.Flat anvil and method free from Mannesmann effect（FM） are commonly used in chamfering process of forging nuclear turbine low-pressure rotor.It causes the strain of billet to concentrate on surface areas and wastes the heavy reduction of chamfering process.Process improvement using V-shaped anvil in chamfering process to improve the internal quality of heavy forgings is brought forward and the stress and strain distribution are investigated by means of the combination of physical and numerical simulations.Results show that the contact between V-shaped anvil and forging can increase the hard deformation area of forging surface.So using V-shaped anvil,especially with low angle,in the chamfering process can increase the deformation at the center of the billet and improve the stress state of the center part.Rational staggering anvil process can reduce hard deformation area at the center of the billet during chamfering.It is suggested to use V-shaped anvil in chamfering process with angle of anvil below 120°,reduction above 20% and rational staggering anvil process.

关 键 词：大型锻件 V形砧 数值模拟 物理模拟 锻造工艺 

分 类 号：TG316[金属学及工艺—金属压力加工]