How to solve the wear and tear of Henan impact crusher

How to solve the wear and tear of Henan impact crusher

The main form of ball failure is wear, broken and out of round ( Henan counterattack crusher    PF impact crusher   Heavy Hammer Impact Crusher ) . Breaking and out-of-round reduce the grinding efficiency, and at the same time it accelerates the wear of the grinding ball. In general, wear is the main cause of failure.

The main mechanism of abrasion of the grinding ball under the mutual compression between the material, the lining plate, and the grinding balls is:

( 1 ) Cutting and chiseling wear. The force acting on the grinding ball surface can be decomposed into normal force and tangential force. The sharp material (grit) that moves relative to the grinding ball is embedded on the surface under the action of normal force, and the tangential force moves the abrasive grain along the surface. . Low-hardness abrasive grains produce shallow scratches on the surface of the grinding ball, while high-hardness abrasive grains create cutting grooves. Metals in the scratches and grooves are deformed and deposited on both sides and the front section. The high strain rate causes the internal dislocations of the metal that have undergone plastic deformation to plug up and form a cell structure. The properties become hard and brittle. After repeated rolling, strain fatigue cracks are generated, and the properties become hard and brittle, and then undergo repeated rolling to produce Strain fatigue cracks, spread to the surface, causing the wear debris to fall off. When the abrasive particles act on the surface of the grinding ball, the chiseling action occurs to form a chisel pit, and the metal is directly deformed or plastically deformed, and the iron scrap is formed due to strain fatigue.

( 2 ) Fatigue wear. The ball is repeatedly impacted and squeezed and slid between each other under repeated impact stress, contact pressure stress and shear stress, and the alternating Hertzian contact stress is caused by alternating pressure and shear force. In the subsurface layer of the material, large alternating shear stress is generated, and the peak tensile stress occurs at the edge of the contact zone, resulting in fatigue cracks in the sub-surface brittle phase, inclusions, or voids, crack propagation and interweaving, and finally exfoliation and wear of the ball. . If cracks occur in deeper parts, they propagate inward along the brittle phases and defects, creating large deep cracks. The cracks will merge into the surface and cause the surface of the ball to fall off. The ball wears on the surface;

( 3 ) Brittle wear. In wet ball mills used in mines, the wear medium (belonging to the electrolyte solution) and the above-described wear conditions act together on the surface of the material and corrode and wear. Wet grinding consumes more than dry grinding of 5 to 7 times. The rate of material loss under the corrosion wear mechanism is much higher than the sum of corrosion and wear alone due to the material loss rate. Corrosion damages the mechanical properties of the material surface and causes the material to wear out at an accelerated rate. The wear continues to produce “new” material surfaces that increase the rate of corrosion.

According to the above analysis of the wear mechanism of the ball failure type, to improve the service life of the ball, the material should have high hardness, high impact fatigue strength, high fracture toughness and impact toughness and some other mechanical properties. On the other hand, ball mill parameters also affect the wear and fatigue life of the ball.