Process of high temperature alloy thin-walled castings ring size control

Superalloy castings bicyclic complex thin-walled casing structure, Support plate with a plurality of hollow and uneven thickness, Makes the casting during cooling, the shrinkage is inconsistent, resulting in the casting, and the outer diameter of the unstable deviated from the design drawings.
By analyzing the entire casting process and technology solutions to the contraction of the casting, find out the reasons for casting deviation from the basic design requirements and rules, and repeated measurements mold, wax, metal parts, data analysis, an improved scheme, and a program of verification, casting size has been effectively improved to meet the design requirements.
In order to meet aviation engine structure lightweight, low-cost needs, the aviation industry has been using high-temperature alloy thin-walled casing overall precision casting technology to replace the split parts processing, assembly casing molding manufacturing technology, High-temperature alloy thin casing whole cast has been different from the traditional sense cast. Not only requires forming, casting needs precise control of the shape, size precision to meet the requirements of the assembly member. We developed the K4169 superalloy thin-walled castings casing is such a typical casting parts, not only the cast inner, outside of metallurgical quality, surface quality requirements, while casting dimensional accuracy requirements more stringent, On the size of the casting Ф800 mm diameter, the tolerance is 0.6mm, and to ensure the casting surface of the flow channel inlet and exhaust area meet the design requirements, casting, machining, assembly and other manufacturing dimensional accuracy requirements as a whole, are guaranteed by the casting, casting size control is very difficult, in practice the choice of process parameters and mold design revised in accordance with the traditional experience design, it can not meet the requirements of the final product.  
 For the high-temperature alloy castings housing annulus, the outer ring size can not fully meet the design requirements, a series of experimental studies conducted through the casting process scheme of analysis, curing, tooling, castings and other size measurement, data analysis, simulation design, worked out the law of thin-walled annular shrinkage structure and with different flow channel cross-sectional dimensions of the ceramic core contraction differences,readjusted mold design parameters and determine the mold improvement program, the casting size to meet the design requirements.