Selection of blade material of cemented carbide shield knife-1

       The shield cutter is composed of a hob and a scraper. The choice of steel material for the hob ring is very important



The material of the hob cutter ring, according to the working conditions of the cutter ring, the cutter ring material should meet the following properties:



1. High yield strength to avoid crushing deformation of the blade end under high stress;



2. High enough hardness to increase wear resistance and reduce wear of cutter ring;



3. Good impact toughness, improve the crack propagation power of the material, and prevent the cutter ring from breaking;



4. Good anti-tempering performance, improve the thermal stability of the material, and ensure that the cutter ring does not reduce the hardness during the process of hot loading and rolling the rock mass;



5. Good process performance of hot and cold processing, low material cost.



The cutter ring matrix must not only have good wear resistance, but also ensure high impact toughness. The most important internal influence that affects the wear resistance of shield hobs is the chemical composition of the tool material. The following measures can be taken to improve the performance of the hob:



1. Control the carbon content of tool materials;



2. Adding chromium, molybdenum, vanadium, silicon and other secondary phase forming elements to the steel intentionally increases the number of precipitated phases to form fine and dispersed coherent and semi-coherent hard spots, thereby improving the resistance to a certain extent Abrasiveness

3. By adjusting the content of each element, control the content, shape and distribution of each carbide, thereby effectively improving the wear resistance of metal materials.