Study On Bimetal Casting Lining Board Used In Ball Mill

Lining board, which is liable to be damaged, is used to protect cylinder from being impacted and worn directly by materiel and grind-ball. At present, Hadifield steel which has nice ductility, poor abradability and 1ow yield strength is the most widely used material for lining board. Hadifield steel is easy to deform, which leads to lining board Pull-off, and is impossible to match with high hardness and wearability of grinding ball. High-chromium cast-iron has good wearability of which service life is 2~6 times more than that of Hadifield steel in dry work condition though it is brittle. In enduring stated wallop and in work condition of grinding abrasion, it appears fracture failure, showing lack of toughness. Therefore, it is unsafe to make lining board of large-scale bal1grinder with high-chromium cast-iron.This paper researches the use of lining board in the world and domestic. For li1ning board shoud both have nice ductility and nice wearability, bimetal casting is adapted to produce it. That is to say that the high quality steel which has nice toughness and the high-chromium cast-iron which has nice wearability will be compounded together by the method of bimetal cast. As a result, the abrasive surface has excellent wearability while the matrix has excellent toughness.In this paper, the effect of chemical constituents, casting technique and heat treatment parameters on the rigidity, microstructure and abradability of bonding pad was researched using HR-150A Rockwell hardometer, Olympus Microscope, SEM, EDAX, ZBC-300 Charpy impact machine tester, MLD-10dynamic load abrasion tester respectively.The results show that the nature of bonding pad of bimetal casting lining board is better than that single high carbon steel. Lining board has maximum value of impact toughness of 23J/cm2 at austempering temperature of 290℃. Fracture existing in high-carbon steel is mainly brittle fracture followed with gliding fracture. The abrasion resistance is more than twice of the Mn13 after isothermal quenching of the sample. Under the conditions of experiments of 1 hour wearing-in period, 150 turns per minute of the impact machine, and 0.1～4mm abrasive particles, the sample has the best wear resistance. Bimetal composite casting would lead to metallurgical bonding, and integrally have nice wearability and excellent toughness. Of all the samples, the one austenitized at 860℃and austempered at 290℃wi11 perform the best. Its service life is 40% more than that of samples made of domestic common high manganese steel.