Heat treatment method for improving high-niobium reinforcing type monocrystal high temp alloy use property

A heat treatment method and superalloy technology, applied in chemical instruments and methods, post-treatment, single crystal growth, etc., can solve the problem that the strength potential of cast IN718 alloy cannot be fully realized, and achieve the purpose of expanding the scope of use, improving plasticity and improving strength. Effect

Inactive Publication Date: 2004-06-09
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, the strength potential of the cast IN718 alloy cannot be fully utilized

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Example 1 Treatment of Single Crystal IN718 Alloy

[0015] A homogenization and aging heat treatment system of the present invention for high-niobium-strengthened superalloys is as follows: take the single-crystal cast IN718 alloy as sample 1, heat it at 1160°C for 20 hours, eliminate the harmful phase Laves phase and niobium segregation, and the alloy The melting point rose to 1240°C. Then heat the alloy to 1240°C, keep it warm for 20 hours, and air-cool (homogenization treatment); keep it at 720°C for 8 hours, cool it to 620°C at a cooling rate of 50°C per hour, keep it at 620°C for 8 hours, and air-cool (aging treatment).

[0016] Take another sample of the same material and size using a conventional heat treatment system (J.T.Guo, L.Z.Zhou, The effect of phosphorus, sulfur and silicon, on segregation, solidification and mechanical properties in cast alloy 718.in'Superalloys 1996', eds.By R.D.kissinger et al., TMS, 1996, p.451) treatment: heat preservation at 1090°C...

Embodiment 2

[0021] Embodiment 2 is to the processing of IN718 alloy

[0022] The single-crystal cast IN718 alloy was taken as specimen 2, which was subjected to high-temperature homogenization treatment, that is, heat preservation at 1145°C for 25 hours, to eliminate the harmful phase Laves phase and niobium segregation, and the melting point of the alloy rose to 1240°C. Then heat the alloy to 1200°C, keep it warm for 30 hours, and cool it in air; then carry out conventional aging treatment to precipitate the strengthening phase, that is, keep it at 720°C for 8 hours, cool it to 620°C at an average speed of 50°C per hour, and keep it at 620°C for 8 hours. air cooled.

[0023] The cast polycrystalline IN718 alloy was treated by hot isostatic pressing heat treatment in the prior art: after hot isostatic pressing: 1121° C., 102.9 MPa pressure, heat preservation for 3 hours. Then keep it at 1065°C for 1 hour, keep it at 718°C for 8 hours, cool it to 621°C at an average speed of 50°C per hour...

Embodiment 3

[0026] Embodiment 3 to the treatment of K718 alloy

[0027] Select (single crystal) K718 alloy as specimen 3, the difference from Example 1 is that the homogenization treatment is a stage:

[0028] 1. High temperature homogenization treatment:

[0029] Place the sample in a temperature environment of 1170 ° C to eliminate harmful phases and increase the melting point of the alloy, and keep it warm for 50 hours until the Laves phase of the test piece is dissolved and Nb segregation is eliminated;

[0030] 2. Conventional aging treatment precipitation strengthening phase:

[0031] The aging treatment adopts the standard aging treatment system of high-niobium strengthened alloys: heat preservation at 720°C for 8 hours, cooling in a uniform furnace to 620°C for 2 hours, heat preservation at 620°C for 8 hours, and air cooling.

[0032]In addition, the conventional heat treatment of polycrystalline casting is adopted (Zhao Jingchen, Wang Bin, Sun Jiahua, Effect of homogenization t...

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PUM

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Abstract

The present invention discloses a heat treatment method for improving usability of high niobium strengthened monocrystal high-temp. alloy, and said method includes the following steps: 1). high-temp. homogenization treatment: placing sample in 1140-1170 deg.C temp. environment, heat-insulating for 5-30 hr. to eliminate harmful phase and niobium segregation, and cooling; and 2). conventional ageing treatment to separate out strengthening phase so as to obtain the invented product.

Description

technical field [0001] The invention relates to a heat treatment method for improving the service performance of a high-niobium reinforced single crystal superalloy. Background technique [0002] Superalloys are key materials for manufacturing aviation, aerospace, ship engines, and gas turbines for thermal power plants. Taking aero-engines as an example, increasing the air inlet temperature, increasing the thrust-to-weight ratio, reducing the weight of the engine, and improving the safety and durability of the engine are the keys to improving and increasing the performance level of the engine. The realization of these goals directly depends on the production and use of superalloys with excellent microstructure and properties. Among a wide variety of high-temperature alloys, high-temperature alloys with niobium as the main strengthening element occupy an important position. This type of alloy can precipitate a large amount of γ″(Ni 3 Nb) phase, the strengthening effect is ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22F1/10C30B29/52C30B33/02
Inventor 孙文儒郭守仁佟百运卢德忠李娜胡壮麒
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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