Material and processing optimization on disc cutter of tunnel boring machine for failure prevention

• Published in: Engineering failure analysis Vol. 138; p. 106363
• Main Authors: Li, Jie, Gong, Yi, Zhao, Shu-peng, Sun, Wei-Lian, Xu, Yang-yang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022
• Subjects: Disc cutter; Failure prevention; Heat treatment; Tunnel boring machine; Failure prevention; Heat treatment; Tunnel boring machine; Disc cutter
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2022.106363

•The optimum heat treatment process of 42CrMo low alloy steel as disc cutter ring material was investigated.•The chemical composition of 42CrMo low-alloy steel was analysed.•The impact absorbed energy, hardness and wear resistance of 42CrMo low-alloy steel and had undergone different heat treatment processes were investigated. During the excavation process of hard rock tunnel by tunnel boring machine, rock breakage is mainly realized by the disc cutter, of which the cutter ring is in direct contact with the rock and therefore is prone to failures like wear, distortion and fracture. In this paper, in order to prevent the frequently-occurred failure of the cutter rings made of H13 medium-alloy steels, the properties of the specimens that were made of 42CrMo low-alloy steel and had undergone different heat treatment processes were investigated, including chemical composition, impact absorbed energy, hardness and wear resistance. The results pointed out that the combination of quenching at 850 °C and tempering at 180 °C and 230 °C was the optimum process, through which increased impact absorbed energy, equivalent hardness and wear amount was achieved in comparison with that of the H13 specimen. Achievement of this paper will facilitate both failure prevention and cost reduction for the disc cutter of tunnel boring machine.