多次电镀铬对30CrMnSiNi2A疲劳寿命和氢脆性能的影响

Influence of repeated chromium plating on fatigue life and hydrogen embrittlement performance of 30CrMnSiNi2A

飞机在服役过程中会多次返修,在30CrMnSiNi2A表面进行多次电镀铬处理,因此系统研究多次电镀对30CrMnSiNi2A疲劳寿命和氢脆性能对飞机返修中的零件重复利用有重要的意义。本文对电镀前和多次电镀后的30CrMnSiNi2A进行疲劳寿命、氢脆性能和疲劳断口形貌分析,考察了多次电镀对30CrMnSiNi2A性能的影响。疲劳寿命测试和断口分析表明,一次电镀铬后,30CrMnSiNi2A的疲劳寿命降低60%以上;多次电镀后的试样与一次电镀后的试样的疲劳寿命维持在相同水平。未经电镀的试样断口呈现单一疲劳源的韧性断裂特征,多次电镀后的试验断口呈现多疲劳源的脆性断裂特征。疲劳裂纹主要起源于镀层和材料基体的界面,疲劳寿命降低与镀铬层的特性相关。氢脆实验结果说明多次电镀对30CrMnSiNi2A的氢脆性能无明显影响。

The aircraft will be repaired many times during the service process,and the surface of 30CrMnSiNi2A will be electroplated for many times.Therefore,it is of great significance to systematically study the fatigue life and hydrogen embrittlement performance of 30CrMnSiNi2A by multiple electroplating for the reuse of parts in aircraft repair.In this paper,the fatigue life,hydrogen embrittlement performance and fatigue fracture morphology of 30CrMnSiNi2A before electroplating and after multiple electroplating were analyzed,and the influence of multiple electroplating on the properties of 30CrMn‐SiNi2A was investigated.Fatigue life test and fracture analysis show that the fatigue life of 30CrMnSi‐Ni2A is reduced by more than 60%after one electroplating of chromium;the fatigue life of the sample after multiple electroplating is maintained at the same level as that of the sample after one electroplating.The fracture of the sample without electroplating presents the ductile fracture characteristics of a single fatigue source,and the test fracture after multiple platings presents the brittle fracture characteristics of multiple fatigue sources.Fatigue cracks mainly originate from the interface between the coating and the material matrix,and the reduction in fatigue life is related to the characteristics of the chromium coating.The results of hydrogen embrittlement experiments show that multiple electroplating has no obvious effect on the hydrogen embrittlement performance of 30CrMnSiNi2A.