大锻件微孔隙氢致内力耦合作用对裂纹扩展的影响

Infuluence of Micropores and Crack's Hydrogen Induced Stress Coupling Effect on Crack Growth in Heavy Forging

基于大锻件氢压理论,从断裂力学角度出发,建立了微裂纹与微孔隙耦合作用的力学判据,采用有限元法分析了不同情况下微孔隙的耦合作用对微裂纹断裂参量的影响。分析结果表明,微裂纹的扩展受微孔隙氢压应力场的影响十分明显,其效果和强度与微孔隙的尺寸和位置有关,在相同的尺寸下孔洞类微孔隙对微裂纹扩展影响最大。分析结论为大锻件内部裂纹扩展研究提供了理论基础。

Based on hydrogen pressure theory in heavy forging,the mechanical criteria for crack coupling with other micropores was established from the fracture mechanics,and the impact of micropores＇ coupling effect on crack＇s fracture parameters under different conditions was analyzed by finite element method.The results indicate that the influence of micropore＇s hydrogen stress field on the crack＇s propagation is very obvious,and the effect and intensity of impact are connected with the size and position of micropores.In addition,the void-microspores have the greatest effect on crack propagation under the same micropore size.The analysis conclusion provides the foundation for the study of crack propagation in heavy forging.