Melting in the molten iron is too saturated, with hot metal temperature drop Lacey sell graphite, carbon, graphite precipitation in the form of the casting surface defects ductile iron, compacted graphite iron and other iron-carbon equivalent prone. Often appear in the casting thick at the surface, a lower surface of the sand core or casting solidification last place, such as riser, riser neck edge. It was a dense dark spots (glossy black), a large number of spherical-shaped blossom, dendritic graphite aggregation. This is also a density segregation, macroscopic fracture was continuous and uniform distribution of graphite, color uniform layer of black spots, microscope low magnification (20 to 40 times) was significantly observed gather graphite; 100 times under observation, dense clusters of graphite or connected together. The area of ??high carbon content, magnesium, rare earths, sulfur is also high, hardness, tensile strength, impact toughness decreases. Pure charge subcooling large, is not conducive to the nucleation of graphite precipitation, less float. The main measures should be controlled to prevent the carbon equivalent according to the casting wall thickness; when small pieces of the wall thickness of not more than 30mm, appear critical carbon graphite floating equivalent of 4.7% - 4.9%; when the wall thickness of 30 to 100mm, appear critical carbon graphite floating equivalent of 4.5% - 4.6%; float appeared critical graphite carbon equivalent of 4.4% ~ 4.5% when the large wall thickness greater than 100mm. In particular, to control the carbon is less than 4. O%; the appropriate use of scrap, pig iron and silicon lower back with the use of charge; controlling the residual amount of rare earth is not too high; pouring temperature control; large cross section castings may be appropriate to add molybdenum or partial placement also prevents cold iron graphite float (see carbon equivalent cast iron, ductile iron). Graphite products have chemical stability and resistance to erosion. Graphite has good chemical stability at room temperature, without any strong acid, alkali and organic solvent erosion. Therefore graphite, graphite products, even if long-term use of graphite mass loss are rarely roughness, as long as wipe clean still like new. Graphite products with a strong oxidation and reduction of the role. Products in particular, can have a negative oxygen ions mattress after graphite heating, activation of the surrounding objects, maintain health, prevent aging, skin shiny and elastic. Pingdu graphite, graphite, carbon industry is provided by the North Sea Dragon Sea Dragon Carbon Co., Ltd. Weifang. Carbon Co., Ltd. Weifang Sea Dragon (www.longmentanye.com) strong, credible, Shandong Weifang graphite and carbon products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the industry in the North Sea Dragon carbon into the brilliant and you work for a better future!