Abstract： Under the actual production condition of the traditional technique, it is easy that high chrome white cast iron grinding media forms more internal stress, which is lead to disabled main reason in production and employ condition. The importance of grinding ball cast microstructure is known by analysis hot working whole process, that is, required […]
According to GB9441-88, the spheroidizing grade of each furnace number sample and grinding ball is above 1 ~ 2 grade, the size of spheroidal graphite is above 7 ~ 8 grade (100 times Figure 2), the number of graphite balls is more, and the distribution is uniform, the matrix structure (1000x Figure 3) of the […]
After analyzing the elements of grinding ball material for Bainite Ductile Iron Balls, goes to the next step– casting and melting process. Wet sand molding, alloy melting in a one-ton cupola. (1) metal charge: High Quality No. 18 Benxi pig iron, return iron, ferromolybdenum, ferrosilicon, Ferromanganese, scrap steel, return charge, and spheroidized alloy. These metal […]
Abstract: The heat treatment process of step isothermal quenching of casting waste heat can be used to produce low alloy (Mo, Mn, Cu, CR) ductile iron grinding ball materials; its matrix structure is lower bainite with a small amount of martensite, retained austenite and carbide, impact value is more than 14J/CM2, hardness is 52 ~ […]
Through the reasonable design of the chemical composition, strict control of the content of each element, through metal mold casting process and rapid cooling scheme, as-cast austenite, matrix structure, austenite occupied, volume content 55% ~ 70%, carbide content 20% ~ 26% can be obtained.
Abstract: The production process and key points of austenitic high chromium cast iron grinding ball are introduced. Because of its as-cast austenite structure, it has high impact toughness. In addition, in the condition of impact friction, the microstructure will change to martensite, which will produce a work-hardening phenomenon. The material has high toughness and high […]
2.2 Analysis of Gouge test results Each group of chromium grinding media balls into the cone-shaped cylinder body, artificial hammer gouge, and gouge results are shown in Table 2. According to the gouging results, the most frequent place of debris produced by grinding ball is at the boundary of metal mould, and the test results […]
Abstract: Through the falling test and chiseling-hammering test conducted with the metal-sand composite mould cast low chromium grinding balls, it was concluded that the peeling phenomenon had occurred with many balls before their early failure. The cracking initiated at the area of interface between the metal mould and sand mould, then the debris peeling occurred, […]
2.4 Low-magnification analysis In order to further analyze the material quality of the dia90 mm low chromium cast grinding ball, the sample was taken at the fracture position parallel to and close to fracturing by electric spark cutting method. The sample was polished by grinding wheel and heated to about 70 °C in 50% hydrochloric […]
2.3 Metallographic test With the hardness mentioned above test samples, the metallographic samples were prepared near the fracture point, polished and polished without erosion at 100-fold optical. Non-metallic inclusions were detected under the microscope. The results are shown in Table 2 and Figure 2.