Failure analysis of a lancing tool used in a bridge slot filter pipe machine

Failure of a lancing system was investigated. A local company produces bridge slot screen filter pipes. Specific cutting tools, part of the lancing system, brake down repeatedly. The parts were manufactured from AISI D2 steel. A systematic investigation consisting of on site inspection, visual examination, dimensional verification, hardness measurements and chemical analysis was carried out. Samples were selected and prepared for destructive testing. The fracture surfaces and the cross section of the tools were analyzed by light and SEM microscopy. The tools failed due to high shear stresses, unevenly developed on the surface of the parts. Their breakage is mainly attributed to poor design. The cutting-forming system should be redesigned and some aspects regarding the machine use and maintenance should be specified. Additionally, alternatives regarding the material selection of the tools are provided in order to ensure efficiency and to improve operational reliability.