硬岩掘进盾构机刀圈的热处理

Heat treatment of tunnel boring machine cutter ring for hard rock

采用电渣重熔、多向锻造和超细化处理对刀圈用H13钢的微观组织进行了优化,并对优化后的H13钢进行了常规热处理,分析该钢硬度与冲击韧性之间的关系,据此对H13钢刀圈进行弹硬热处理。结果表明:经弹硬热处理后,刀刃形成回火马氏体组织,硬度提高至59 HRC;刀座形成回火托氏体组织,硬度降低为44 HRC,冲击吸收能量升至23.5 J,实现了高硬刀刃与高弹刀座的性能配合,进而使刀圈具有收缩回弹的弹性特点,显著提高刀圈的使用寿命与破岩效率。

The microstructure of H13 steel for cutter ring of tunnel boring machine was optimized by electroslag remelting,multi-directional forging and ultra-refining treatment. The optimized H13 steel was first subjected to conventional heat treatment to analyze the relationship between the hardness and impact toughness of the steel. According to this,the H13 steel cutter ring was subjected to the elastic hardening heat treatment. The results show that after the elastic hardening heat treatment,the blade edge forms a tempered martensite microstructure and the hardness is increased to 59 HRC;but the blade seat forms a tempered martensite microstructure,the hardness is reduced to44 HRC,and the impact absorbed energy is increased to 23. 5 J,achieving the combination of the high-hardness blade and the high-elasticity tool holder,which makes the cutter ring have the elastic characteristics of contraction and rebound and significantly improve the service life and rock breaking efficiency of the cutter ring.