Directional solidification method capable of eliminating spots in casting

A directional solidification and casting technology, applied in self-solidification methods, chemical instruments and methods, crystal growth, etc., can solve the problems of low temperature gradient and concave solidification interface, achieve high temperature gradient, wide material sources, and eliminate freckles. Effect

Inactive Publication Date: 2016-09-28
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem of freckles due to the low temperature gradient of the cross-sectional mutation region and the concave solidification interface during the directional solidification process of the existing cross-sectional mutation casting, the present invention proposes a directional solidification method that can eliminate the freckles in the casting

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  • Directional solidification method capable of eliminating spots in casting
  • Directional solidification method capable of eliminating spots in casting
  • Directional solidification method capable of eliminating spots in casting

Examples

Experimental program
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Embodiment 1

[0037] This embodiment is applied to the directional solidification process of a casting 1 with a sudden change in cross section, such as figure 1 shown. The size of the small section of the casting with sudden change in cross section is 4mm×20mm×100mm, the size of the large section of the casting is 40mm×20mm×25mm, and the material is CMSX-4 superalloy; the specific steps are as follows:

[0038] Step 1, determine the temperature gradient distribution and solidification interface shape during the directional solidification process of the casting. Use ProCAST software to numerically simulate the directional solidification process of casting 1 according to conventional methods, and perform post-processing to obtain figure 1 The temperature gradient distribution and the shape of the solidification interface in the cross-sectional sudden change region shown in A are as follows: figure 2 a with Figure 4 as shown in a.

[0039] Step 2, determine the shape, size and placement...

Embodiment 2

[0052] This embodiment is applied to the directional solidification of a casting 1 with a sudden change in cross section, such as figure 1 shown. The size of the small section of the casting with sudden change in cross section is 4mm×20mm×100mm, the size of the large section of the casting is 40mm×20mm×50mm, and the material is DZ411 superalloy; the specific steps are as follows:

[0053] Step 1, determine the temperature gradient distribution and solidification interface shape during the directional solidification process of the casting. Use ProCAST software to numerically simulate the directional solidification process of casting 1 according to conventional methods, and perform post-processing to obtain figure 1 The temperature gradient distribution and the shape of the solidification interface in the cross-sectional sudden change region shown in A are as follows: image 3 a with Figure 5 as shown in a.

[0054] Step 2, determine the shape, size and placement position...

Embodiment 3

[0067] This embodiment is applied to the directional solidification process of a casting 1 with a sudden change in cross section, such as figure 1 shown. The size of the small section of the casting with sudden change in cross section is 4mm×20mm×100mm, the size of the large section of the casting is 40mm×20mm×25mm, and the material is DZ125 superalloy; the specific steps are as follows:

[0068] Step 1, determine the temperature gradient distribution and solidification interface shape during the directional solidification process of the casting. Use ProCAST software to numerically simulate the directional solidification process of casting 1 according to conventional methods, and perform post-processing to obtain figure 1 The temperature gradient distribution and the shape of the solidification interface in the cross-sectional sudden change region shown in A.

[0069] Step 2, determine the shape, size and placement position of the graphite block. According to the principl...

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Abstract

The invention provides a directional solidification method capable of eliminating spots in a casting. The purpose of eliminating the spots is achieved by replacing part of a mold case in a cross-sectional abrupt change area with a graphite block with a certain shape and size, having an excellent heat conducting property. The temperature gradient of the cross-sectional abrupt change area of the casting is improved, and a solidification interface tends to be horizontal, so that an arborescent structure is possible to be refined, flowing resistance increases, and the tendency that segregation melt partially clusters decreases. Therefore, the spot forming tendency decreases. The graphite block is placed at the bottom of a platform in the cross-sectional abrupt change area of the cross-sectional abrupt change casting, the temperature gradient of the cross-sectional abrupt change area of the casting is improved, the solidification interface tends to be horizontal, and spot defects are eliminated. The directional solidification method has the characteristics of simple and feasible application and implementation, wide sources of materials and low cost.

Description

technical field [0001] The invention belongs to the field of directional solidification of nickel-based superalloys, in particular to a directional solidification method capable of eliminating freckles on the surface of blade castings with abrupt cross-section changes. Background technique [0002] Because the size and quality of gas turbine blades are much larger than those of aeroengine blades. Therefore, the commonly used high-speed solidification method (HRS method) directional solidification technology that eliminates transverse grain boundaries and obtains directional grains or single crystals increases the probability of casting defects such as freckles due to insufficient cooling capacity and other reasons. Freckle defect A macro-segregation consisting of shrinkage porosity, eutectic, broken dendrite arms, etc., which reduces the high-temperature mechanical properties of the blade. [0003] It is generally believed that the formation of freckles is related to heat a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22D27/04C30B11/00C30B29/52
CPCB22D27/045C30B11/00C30B29/52
Inventor 李秋东沈军秦岭
Owner NORTHWESTERN POLYTECHNICAL UNIV
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