电焊机2025，Vol.55Issue(5)：55-62,8.DOI:10.7512/j.issn.1001-2303.2025.05.07
单调载荷下Q345B晶粒与晶界强度协调数值模拟研究
Numerical Simulation of Q345B Grain and Grain Boundary Strength Coordination under Monotonic Loading
摘要
Abstract
Due to the differences in the microscopic mechanical properties of metal material grains and grain boundaries,plastic cumulative slip first occurs within the grains under low-stress cyclic loading until it extends to the vicinity of the grain boundaries,eventually forming initial cracks.In order to deeply understand their microscopic mechanical behaviors,the crystal plastic finite element method was adopted to construct a microstructure model considering the strength differ-ences between micro-grains and grain boundaries,and numerical simulation studies under monotonic loading were carried out.Based on the scanning electron microscope(SEM)images of the microstructure,a microstructure finite element model was established through topological geometry,and a coordinated constitutive relationship between grains and grain boundar-ies was constructed by using the ratio of the difference in strength between grains and grain boundaries.When the grain strength is about 90%of the macroscopic strength,the numerical simulation results under the coordinated strength of the grain boundary and the grain are closer to the actual tensile test results.This study reveals the influence of the strength coor-dination mechanism between grains and grain boundaries on the mechanical properties of materials,laying a foundation for subsequent research on the fatigue properties of materials under cyclic loading.This research innovatively introduces the strength difference between grains and grain boundaries into the numerical model,and verifies the accuracy of the model through the comparison between simulation results and experimental data,providing a new perspective for deeply under-standing the relationship between the microstructure and macroscopic properties of materials.关键词
疲劳/微观机制/数值模拟/晶粒晶界/强度协调Key words
fatigue/microscopic mechanism/numerical simulation/grains and grain boundaries/strength coordination分类
矿业与冶金引用本文复制引用
胡广旭,丁人杰,刘洋,席慧智,巩庆涛..单调载荷下Q345B晶粒与晶界强度协调数值模拟研究[J].电焊机,2025,55(5):55-62,8.基金项目
国家基金委-山东联合基金(U2006229) （U2006229）
山东省重点研发计划(重大科技创新工程)(2020CXGC010701) （重大科技创新工程）
