Effect of tempering temperature on the microstructure, mechanical properties and abrasive wear behavior of a new C–Cr–Mo–V alloy steel used in TBM cutter ring

Tunnel boring machine (TBM) cutter ring material is a type of C–Cr–Mo–V alloy steel which possesses high hardness and wear resistance. To systematically study the effect of tempering temperature on the microstructure, mechanical properties and abrasive wear behavior of TBM cutter ring, a new C–Cr–Mo–V alloy steel (DB3) was subjected to tempering treatment and abrasive wear test. The results indicate that the tempering temperature controlled the hardness and toughness by adjusting the amount of precipitates and austenite transformation. Outstanding mechanical properties were obtained upon tempering at 520 °C. The wear resistance of DB3 steel was mainly controlled by hardness under non-impact abrasive wear condition. However, under the condition of impact abrasive wear, the wear resistance of DB3 steel was affected by hardness and toughness, and only in a certain range of toughness, the wear resistance increased with the increase of hardness. The experimental results can provide some reference for the heat treatment process of DB3 steel used in TBM cutter ring.