Preliminary examination of a premature failure in a cold-working die for sheet-metal cutting

Résumé

The present work studies the premature failure of a cold-working die for sheet-metal cutting. The tool was made of AISI O1 steel and was produced for cutting metal sheets of up to 2 mm thick. The die failed during the manufacturing process, during the fine face-grinding. After the specific procedure, the cutting surface exhibited a uniform pattern of cracks, to an extend that lead to the rejection of the die. The paper refers to preliminary examination of the failed tool. Data concerning tool production, manufacture and maintenance were collected. The die was subjected to visual inspection, dimensional changes of the part were examined and non-destructive testing was used for the examination of the cracks. Chemical analysis was performed in order to identify the die’s material. The paper presents conclusions on the type of failure and the possible reasons that led to it. The conclusions may be of interest in providing information on avoiding similar situations.