Henan Prosperous refractory riser

A casting mold for casting feeding storage with molten metal, and exhaust residue collection action cavity. In the mold, the riser cavity is stored liquid metal cavity, supplies metal formed during casting, to prevent shrinkage, shrinkage, and set the role of exhaust slag. Different functions riser, its form, size and open positions are not the same, so, riser design must consider the nature and the cast alloy castings characteristics. ① riser for volume contraction during solidification small alloy (eg gray cast iron), or no shrinkage concentrated alloys (such as bronze), riser main function is to discharge cavity in the gas and collect the flow front inclusions or mixed with liquid metal oxide film, in order to reduce defects on the casting. Such multiple riser disposed opposite the gate, do not have too large a size, ② microstructure control requirements for casting, riser can collect flow front of the molten metal has cooled, to avoid casting supercooled tissue . Figure 2 is a single casting of piston rings, including set opposite a small riser to collect the cold metal, where it will not appear because of the metal is too cold and white tissue, leading to casting scrap. Such feeder size and installation position shall be determined by the microstructure of the casting requirements. ③ for large volume shrinkage during solidification shrinkage and tend to form concentrated alloys (such as steel, brass and aluminum manganese bronze, etc.), the main role is to compensate the riser of the solidification of the liquid in the cavity shrinkage and casting contraction process, in order to obtain a dense casting without shrinkage. When the casting is cooled in the mold, the thinnest part before coagulation, which may partially compensate for shrinkage of the thicker nearby; partially solidified when thick, can be compensated by the thickest part; when the thickest part of the coagulation, such as the lack of foreign compensation, where it will form a big crater. In this case, the effect is to compensate for riser casting final solidified portion, the casting to be placed above or the side of the thickest part, and it requires later solidification in the thickest portion of the casting. Figure 3 is a sleeve-shaped castings, has the thickest part of the top three riser, is a dense castings and risk population shrinkage, the casting and a riser cut in half. Figure correction amount is to improve the local thickening of the casting riser and the casting supply additional. Since the riser slowest cooling, shrinkage due to feeding and contraction caused by itself will only produce at risk population. Riser and the correction amount of design related processes such casting process design is an important part of the riser size is generally determined by the calculation method, it is important large castings available computer-aided design. Can improve the efficiency of the riser feeding through a variety of technical measures, such as medium and small castings can add an insulating sleeve or fever sets in around the riser to slow solidification riser riser size reaches narrow purposes; large castings In addition to the available heat insulation kits or sets, but also at the top of the riser with arc or flame heating to slow solidification. Another way to improve the efficiency of riser feeding is taking a different approach to increase pressure on the mouth. Riser types: 1, ordinary feeder: Use ordinary molding material of the riser called ordinary riser; 2, riser: insulation materials made of riser called the riser, the mouth of the liquid metal thermal risk than normal risk mouth solidified long time, saving metal; 2, heat riser: Add heat generating agent in the riser material, after pouring molten metal into a fever agent to heat the metal can be maintained for a longer time in the liquid state, to take over insulation mouth more economical metal.