Manufacturing Process Of Low Chrome Mill Balls

Release time：2021-10-12

New process design of low Chromium white cast iron grinding ball  

 

 

The microstructure of low chromium cast iron grinding ball should be composed of as many hard structures as possible, carbides and martensite with significant morphological changes on the basis of the realization of broken mesh. Meanwhile, it is the design concept and goal of the new technology to reduce and control the internal stress, micro-cracks and discontinuous microstructure in the parts.  The principles of new process design are consistent in the aspects of cooling rate control, composition design, casting metallurgical treatment and heat treatment.  

 

The impact toughness and strength of low chromium white cast iron grinding ball are inferior  

High chromium white cast iron grinding ball.  High chromium ball has high impact toughness  

substrate  

This is mainly due to the M,C type carbonization of high chromium white cast iron  

The object is three-dimensional open skeleton and strip block, chrysanthemum distribution;  Each chrysanthemum is a eutectic group, the carbide in the chrysanthemum heart is small, gradually thick from the heart to the edge.  However, the M and C carbides in the laestenitic eutectic structure of low chromium white cast iron are like spongy forms, which are embedded with austenite, as shown in Figure 1.  It is this closed network brittle phase that seriously reduces its mechanical properties and mechanical properties  

FIG. 1 Schematic model of microstructure and morphology of low chromium white cast iron  

Performance: on the other hand, the existence of reticular cementite is also larger  

 

Affect the hardenability of materials and increase the internal stress of parts, which also  

 

Is the domestic production of low chromium grinding ball manufacturers have been using pearlite  

The cause of matrix structure.  Combined with most service conditions, should  

Cutting mesh, refining and changing the morphology and modification of non-metallic inclusions  

The grinding ball of low chromium white cast iron was advanced under the premise of obtaining better toughness  

Good distribution of the state of metamorphism, inoculation treatment.  Of course, make parts  

Step increase hardness as the guiding principle of process design.  So you  

There are no internal stresses, microcracks and other discontinuities in the structure  

The quantity and size of carbides to be controlled are determined  

And so on, so that the microstructure grain refinement, forming as much fine as possible