Casting method of casting of gas feeding end of high pressure outer cylinder of thick-wall gas turbine

Abstract

The invention relates to a casting method of a casting at the intake end of a high-pressure outer cylinder of a thick-walled gas turbine in the technical field of casting, mainly including casting direction design, riser and subsidy design, and cold iron design. In the method of the present invention, according to the structural characteristics of the casting and the characteristics of uneven wall thickness, an open riser is respectively arranged on the upper side of the flange end of the casting to directly feed the heat joint 1, and a subsidy 1 is provided on the upper side of the heat joint 2 for communication. The feeding channel for thermal festival two and thermal festival one. Set a dark riser on the inner side of the lower part of the casting direction, and form a feeding channel between the dark riser and the hot section 3, hot section 4 and hot section 5 through subsidy 2, subsidy 3 and subsidy 4; the cylinder around the dark riser Cold iron 1 and cold iron 2 are respectively set inside and outside the body, which are used to close the feeding channel between the open riser and the dark riser in advance, so as to realize the partition feeding function of the open riser and the dark riser, and reasonably control the casting Solidification sequence, while ensuring the feeding capacity of the open riser to the upper hot section 1 and hot section 2.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a casting method for a casting at the intake end of a high-pressure outer cylinder of a thick-walled gas turbine. Background technique [0002] The casting at the inlet end of the high-pressure outer cylinder is a heat-resistant steel casting for a supercritical condensing steam turbine. The non-destructive testing requirements are strict, and there must be no casting defects such as slag inclusions, shrinkage porosity, and cracks. The casting structure is as follows: figure 1 and figure 2 As shown, including the cylinder body 1, one end of the cylinder body 1 is provided with a flange end 4 coaxial with the cylinder body, and the two outer peripheries of the cylinder body 1 in the radial direction below the axial center are provided with horizontal horizontal pipes 2, and the two horizontal Cat claws 3 are respectively provided at the angle between the bottom of the horizonta...

AI Technical Summary

Problems solved by technology

[0003] 1) The wall thickness of the axial section is large, the maximum wall thickness is 536mm, and there are many hot spots in the solidification process (hot spots refer to the nodes or local areas in the casting that solidify slower than the surrounding metal during the solidification process, which are called hot spots. This area is easy to produce Shrinkage cavity defect), it is not easy to set riser;

[0004] 2) The heat nodes are scattered and relatively independent, the sequential solidification is poor, liquid feeding is difficult, and casting defects such as shrinkage porosity and shrinkage cavity are prone to occur

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