A method for controlling the grain size of equiaxed superalloy turbine blades

A technology of turbine blades and superalloys, applied in the field of precision casting, can solve the problems of blade inclusions, low pouring temperature, difficulty in meeting the metallurgical quality requirements of castings, etc., and achieve the effect of sufficient feeding and good mold filling.

Active Publication Date: 2021-07-16
AVIC BEIJING INST OF AERONAUTICAL MATERIALS
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to obtain finer grains, this method requires a lower pouring temperature. Too low temperature will bring serious loose defects and cannot completely solve the problem of columnar grains at the exhaust side, resulting in extremely low casting pass rate and high cost
In addition, by adding process ribs or implanting insulation materials inside the shell, changing the local temperature field when the blade is solidified, to solve the problem of controlling the columnar crystals and chilled crystals at the exhaust side of the casting, but this method can only be used in a certain range. To a certain extent, the problem of columnar crystals and chilled crystals on the exhaust side can be alleviated, but it cannot be completely solved
[0004] When the ordinary precision casting method is used for the production of slender and large-sized turbine blades, columnar crystals and chilled crystals are easily formed in the thin-walled areas such as the blade exhaust edge, and the alloy solution solidifies in an instant, making it difficult to feed and easily produce porosity and pores. At the same time, non-metallic oxide inclusions cannot be removed by floating, and metallurgical defects such as inclusions are easy to form inside the blade body, which is difficult to meet the metallurgical quality requirements of castings
Therefore, for slender and large-sized thin-walled turbine blades, it is a great challenge to the casting process to ensure the metallurgical quality of the blade while controlling the grain size.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for controlling the grain size of equiaxed superalloy turbine blades
  • A method for controlling the grain size of equiaxed superalloy turbine blades

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Development of working blades of a low-pressure three-stage turbine for an engine. The blade is a crowned solid blade with a slender shape and a length of about 250mm. The maximum thickness of the blade body is about 3mm, the thickness of the exhaust edge is about 0.8mm, and the weight of a single blade blank is about 380g. It is made of equiaxed nickel-based superalloy K465 (solid The phase line temperature is 1300°C, the liquidus line temperature is 1340°C), and the grain size is required to be 4-7 on the blade body (according to HB 20057). Chilled crystals and vertical columnar crystals are not allowed. In the initial stage of the test, ordinary casting technology was adopted, 4 pieces / group, thick risers were set at both ends of the blade crown and tenon for feeding, and a tall sprue cup was used to form a sufficient pressure head, and the material used for each furnace was 7Kg . In addition, measures such as heat preservation of the sprue and sprue cup wrapped cer...

Embodiment 2

[0041] Development of working blades of a low-pressure five-stage turbine for an engine. The blade is a crowned solid blade with a slender shape and a length of about 230mm. The maximum thickness of the blade body is about 2mm, the thickness of the exhaust edge is about 0.8mm, and the weight of a single blade blank is about 200g. The phase line temperature is 1281°C, the liquidus line temperature is 1327°C), and the surface grain refinement process is adopted, and the grain size requirement is 1-3. In the initial stage of the test, ordinary casting technology was used, 4 pieces / group, and the material used in each furnace was 7Kg. The proportion of blades scrapped due to excessive grain size such as columnar crystals exceeded 30%, and the blade body was seriously loose (exceeding ASTME1921 / 8" Photo 5).

[0042] Adopt above-mentioned steps of the present invention to prepare this kind of engine low-pressure five-stage turbine working blade, at first simplifies pouring system, ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
lengthaaaaaaaaaa
lengthaaaaaaaaaa
lengthaaaaaaaaaa
Login to view more

Abstract

The invention is a method for controlling the grain size of an equiaxed crystal superalloy turbine blade. The invention aims at the slender and large-sized thin-walled turbine blade. By controlling the temperature field of the turbine blade during solidification, the parts of the turbine blade with different thicknesses The formation of uniform equiaxed crystals solves the problem of columnar crystals and chilled crystals in the thin-walled area of ​​the exhaust side of this type of casting; at the same time, the looseness of the blade body is significantly improved through the sequential solidification of the turbine blades, and the qualified rate of the turbine blades is improved. Reduce the cost of blade development.

Description

technical field [0001] The invention relates to a method for controlling the grain size of an equiaxed superalloy turbine blade, belonging to the technical field of precision casting. Background technique [0002] In modern advanced aero-engines, the amount of high-temperature alloy materials accounts for 40% to 60% of the total amount of the engine. Every increase in engine thrust-to-weight ratio is strongly dependent on the progress of superalloys. As the thrust-to-weight ratio of the engine continues to increase, the turbine inlet temperature increases significantly, and the turbine blade material gradually develops from equiaxed crystal alloys to directional, single crystal alloys, and its temperature bearing capacity continues to increase. At present, directional and single-crystal alloys have become the dominant materials for aeroengine turbine blades, but equiaxed superalloys are still widely used in turbine blades with lower temperature bearings, integral blisks, la...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): B22C9/04B22C9/22B22C9/08B22D27/04
CPCB22C9/04B22C9/086B22C9/088B22C9/22B22D27/045
Inventor 宋尽霞黄强王定刚关心光
Owner AVIC BEIJING INST OF AERONAUTICAL MATERIALS
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap