铁质文物裂纹分析

Fracture Analysis of an Iron Cultural Relic

采用断口宏观分析、化学成分分析和金相分析等方法对放置在陈列柜中的某铁质文物开裂原因进行综合分析。结果表明,铁质文物为应力腐蚀开裂。由于陈列柜中放置水,使文物内腔中陶土吸水后腐蚀铁质基体,同时铁质文物内存在铸造应力和焊接应力,导致其内部残余应力较高。铁质文物裂纹是在腐蚀介质和残余应力的共同作用下形成并扩展。

An iron cultural relic fractured in the display cupboard.The failure cause of the cultural relic was analyzed by facture macroscopic observation,chemical composition analysis,metallographic examination and mechanical properties testing and so on.The results showed that there existed stress corrosion cracks in the iron cultural relic,which were caused by water absorbed by the iron cultural relic from the damp air,and existence of the water laid in the display cupboard speeded up the corrosion.The iron cultural relic was a casting art,so there were welding stress and comparatively high residual stress in the iron cultural relic because of the big thickness difference.It can be concluded that the fracture of the iron cultural relic resulted from corrosion and residual stress together.