Fracture Analysis of an Iron Cultural Relic

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.