The Effects of Different Ultrasonic Composite Surface Modifications on the Properties of H13 Steel for Shield Tunnel Machine Cutter Ring

Abstract

Tunnel boring machines (TBMs) are exposed to the impact of the ground shattering force and the friction of sandstone during excavation work, and are prone to wear and breakage, and other failures. Traditional heat treatment processes cannot simultaneously achieve the required high-energy composite structure of hard external and tough internal properties for cutter rings, leading to inadequate wear resistance and impact toughness under working conditions. This study utilizes H13 steel as the base material, and based on a study of carburizing, nitriding, and ultrasonic impact processes for H13 steel analyzing the effects of different high-energy composite modification processes on the hardness distribution, microstructure, and residual stress of H13 steel, the mechanisms by which high-energy composite modification processes affect the wear resistance and impact resistance of H13 steel are revealed. The results indicate that the wear amount and impact toughness of the sample subjected to carburizing and ultrasonic surface rolling composite strengthening were 1.9 mg and 27.34 J/cm2, demonstrating the best wear and impact resistance. This combination of properties allows the H13 steel cutter ring to achieve the optimal overall performance in terms of wear resistance and impact resistance.