25 Cr2 Ni2 MoV钢焊接接头循环变形行为的有限元模拟与分析

以25Cr2Ni2MoV汽轮机转子钢V形平板焊接接头为研究对象，考虑不同热影响区材料与母材的弹性模量比值、坡口角度及载荷特性（包括不同应力比、平均应力和应力幅值）等因素的影响，采用大型有限元软件ABAQUS和Chaboche循环本构模型对接头的循环变形行为、局部塑性变形分布及其随循环周次的演化特性进行了有限元模拟与分析。结果表明，随着热影响区材料与母材的弹性模量比值的增大，焊接接头整体抗拉和抗棘轮变形能力增强，发生局部破坏的可能性也随之增大；随着坡口角度的增加，焊接接头的抗拉性能和抗棘轮变形能力降低；应力比、平均应力和应力幅值越大，焊接接头越容易发生破坏。研究成果实现了对平板焊接接头结构及性能的初步优化，为提高该类焊接接头的设计水平提供了参考。

Numerical Simulation and Analysis for Cyclic Deformation of 25 Cr2 Ni2 MoV Welded Joint

Based on the Chaboche cyclic plastic constitutive model,the cyclic deformation behavior of the 25Cr2Ni2MoV turbine rotor steel plate welded joint of V-style has been simulated and analyzed by em-ploying the finite element code ABAQUS.In the simulations,the evolution features of local plastic deform-ation distribution in the joints and the influence of material properties of heat-affected-zone,groove an-gles and load levels （including stress ratio,mean stress and stress amplitude）on the cyclic deformation behavior of the joint were observed and discussed.It is shown that the tensile and ratcheting resistance of the plate welded joint increase with the increment of the elastic modulus ratio of the heat-affected-zone and base material and the decrease of the groove angles;the failure probability of the plate welded joint are increased while the heat-affected-zone elastic modulus,stress ratio,average stress and stress ampli-tude increasing.Moreover,based on the numerical results,the preliminary optimization of the plate welded joint were obtained,which is useful in the engineering design for the welded joints of such kind.