Supply of steel castings

With steel parts made of steel castings is. And cast iron properties are similar, but better than cast iron strength. Castings prone to bubbles in the casting process, the angular positioning inaccuracies and other shortcomings, there may be housing fracture phenomenon in the long run. Mechanical properties than cast iron high, but its cast iron than poor performance. Because the steel melting point higher, easily oxidized liquid steel, molten steel illiquid, shrink large, its shrinkage rate of 10 to 14% linear shrinkage of 1.8 to 2.5%. Because cast iron shrink significantly exceeds appears to prevent the casting shrinkage, shrinkage defects, mostly using riser and cold iron and subsidies and other measures in the casting process, in order to achieve solidification. Cast high melting point, corresponding its pouring temperature is high. High temperature molten steel and mold material interaction, easy to produce sticky sand defects. Therefore, we should adopt a higher refractoriness synthetic quartz sand mold made, and the brush is made of quartz or zirconium powder sand powder paint was prepared in the mold surface. To reduce the gas source, improve mobility and strength of the mold steel, steel castings mostly dry type or quick-drying to casting, such as the use of CO2 hardened sodium silicate sand. Cast Classification: According to the chemical composition of steel can be divided into carbon steel and alloy steel two categories. 1, carbon steel: in general, low-carbon steel ZG15 higher melting point, casting performance is poor, only for manufacturing electrical parts or carburizing parts; medium carbon steel ZG25 ~ ZG45, has a higher overall performance of various types of cast iron , that is, high strength, excellent ductility and toughness, and therefore suitable for the manufacture of complex shape, strength and toughness requirements of parts, such as train wheels, rack hammer and the anvil, roll and pressure valves are carbon steel Most of the application for a class; high-carbon steel ZG55 low melting point, its performance than in carbon steel casting is good, but its poor ductility and toughness, wear-resistant parts for the manufacture of only a few. 2, alloy steel: according to the total number of alloying elements, alloy steel can be divided into two major categories of low-alloy steel and high-alloy steels.