High manganese steel castings wear resistance is not the higher the carbon content, the more wear-resistant, but there is a limit, when the carbon content of >1.4% after the casting of carbide, water toughness can not completely dissolve into the austenite, the gap-soluble carbide also reached saturation, so not only for the wear resistance, but also to reduce the strength and toughness of materials, It is easy to break in service.
High silicon content reduces the solubility of carbon in austenite, carbide precipitates on the grain boundary increase and hypertrophy, after water toughening, leaves the large microscopic loose in the grain boundary, but in order to completely eliminate, the silicon content in the steel, the control in the 0.4-0.6% best, the silicon content >0.8% has no obvious influence to the high manganese steel performance
These two elements are the natural in pig iron, in the trace alloy elements, they can form a very high hardness of carbon nitride, dispersed in the matrix, is conducive to improving the microhardness and wear resistance of the substrate, while the refinement of the grain is also beneficial. Molybdenum: The main role of molybdenum is to refine the matrix, refining carbide, improve the electrode potential of the substrate, improve corrosion resistance. Because the price is high, it is not economical. Under the condition of metal casting, a small amount can play a significant role in the wear-resisting steel balls with special requirements.
Chromium is a carbide forming element. Chromium in addition to the carbon combined with carbide, the rest are dissolved in the base body, so as to improve the electrode potential of the substrate, to resist corrosion is advantageous. If its content is more than an hour, may appear m3c type carbide, causes the hardness and the toughness to reduce. If its content is large, the number of carbides in crystallization increases significantly, and the toughness decreases, and the hardness of the matrix decreases, which leads to the decrease of wear resistance. But now some manufacturers have adopted special production and treatment technology to solve this problem, so that the content of chromium can reach 30%.
is the formation of austenite elements, the formation of carbide also works, too high manganese will make the organization appear austenite, austenitic tissue is not suitable for grinding ball, because the austenite grinding ball in both dry and wet grinding, will cause a large number of crushing and peeling, but because deoxidation and sulfur are manganese, so the content of manganese in the wear-resistant ball can not be too high.
Phosphorus dissolved in steel rarely, often in the form of fe2p,fe3p in the crystal boundary so that the strength of steel, toughness and wear resistance greatly reduced, carbon content of the high increased p in eutectic form precipitation in the grain boundary. To ensure performance, the following relationships should be followed: c%=11.27-2.761xp%. In production to control phosphorus content ≤0.08%: important, complex, thick wall parts ≤ 0.07%.
Because of the high manganese content in steel, a large number of MNS can be produced from slag. And because it is smelting in alkaline slag, sulfur can be reduced to below 0.03% smoothly. The low sulfur content has no obvious influence on the strength, toughness and wear resistance of the steel.
Nickel (copper) is an austenite forming element, with an increased presence of austenite in the tissue. The main role of adding nickel in troostite grinding ball is to improve the electrode potential of the substrate, and to improve the corrosion resistance, but it is more economical and the micro-function.