Heat-resistant castings in the process of operating with excellent casting can be made into its complex parts, generally has its good cutting processability and shock resistance and abrasion resistance and other advantages, heat-resistant castings price low.
In general, the heat-resistant castings used in the industry are about 4% of carbon content. In the process of operation, the carbon in the cast iron is mostly in graphite form and sometimes in carburized form. In addition to carbon, cast iron also contains 1% ~ 3% of silicon, as well as manganese, phosphorus, sulfur and other elements. Alloy cast iron also contains nickel, chromium, molybdenum, aluminum, copper, boron, vanadium and other elements.
Normally its large heat-resistant steel castings in production process is a complex systems engineering, and production of advanced products to meet domestic demand inevitably involves many new material, new craft, new technology, its key technology is also in the process of manufacturing inevitably involves many fields and aspects in the process of material processing.
Heat resistant castings when to operate mainly of carbon as the main alloying element, and effective contain small amounts of other elements of the cast steel, owing to the high carbon content/heat resistant castings for castings, close to the eutectic, low melting point, good liquidity, little shrinkage, therefore suitable for casting structure or complex thin wall castings. In addition, due to graphite, it is easy to form cuttings during cutting process, and the machinability of gray cast iron is better than steel.
Heat resistant casting hardness is formed in the process of casting pouring, the splash when casting pouring molten steel to form steel beans of different size, so that you can from casting riser in Ming fell into the cavity, if the pouring temperature on the high side, into the steel beans can melt completely, it doesn't make the casting produces the hard point. If the pouring temperature of molten steel on the low side, falling into a part of the steel beans can't completely melting, solidification in casting, especially in the area is large, thin wall casting parts, splashes of liquid steel temperature drops rapidly, some form of steel beans, fall into is taking shape in the liquid steel, sped up the solidification of liquid steel, at the same time matrix grain refinement of the castings.
Solution: when casting steel, to prevent splashes of liquid steel, should be all cast riser with cover sheet iron, casting a box open the box, so that you can avoid the casting hard.http://www.dmgcastings.com/