CRACKING FAILURES OF COPPER ALLOY HOT ROLLED PLATES: PHENOMENOLOGICAL APPROACH AND ROOT CAUSE ANALYSIS

摘要

Failure analysis is performed in copper alloy plates that have been severely fractured during the initial hot rolling passes. Representative case histories, concerning ETP-Cu and Cu-Al-Zn-Sn alloys are outlined in the present study. A comprehensive investigation was conducted, including mainly macroscopic examination, fractographic and metallographic evaluation. Moreover, in the case of ETP-Cu plates, numerical simulation of the solidification front using CFD software was also employed to analyze the influence of the variation of casting parameters on the solidification pattern. Fracture areas manifested poor ductility while in many cases a prior cast pattern consisting of coarsely solidified crystals was revealed. The obtained evidence is suggestive of microstructural embrittlement caused by the synergistic contribution of the manufacturing process conditions and the potential elemental segregation that might aggravate intergranular cracking susceptibility.