Fracture failure analysis and research on super-large-diameter roll

Abstract

A super-large-diameter roll in a roller press suddenly broke in operation after less than four months. A series of experimental tests were carried out to determine the cause of roll failure to evaluate the chemical composition and mechanical properties. A detailed analysis involving macroscopic features and microstructure analysis of the material was performed. Fatigue features were observed on the fracture surface. The crack grew from the edge of the inner hole and extended from the inside to the outside. Further analysis showed that the material had good tensile properties but poor impact toughness. In addition, the roll had an enormous internal stress, far more significant than its working load. The fracture of the roll was a fatigue fracture under unreasonable heat treatment conditions and inner hole design. A larger hole depth and perfect heat treatment are recommended.