A post-weld heat treatment method for improving the corrosion resistance of aluminum-lithium alloy electron beam welded joints

An electron beam welding and post-weld heat treatment technology, applied in heat treatment furnaces, heat treatment equipment, furnace types, etc., can solve problems such as corrosion of aircraft structural materials, impact on aircraft service life, aircraft crashes, etc. The effect of refining the structure and grain, and the technical level is not high

Active Publication Date: 2018-08-31
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Corrosion and damage to aircraft structural materials will affect the service life of the aircraft, and even cause major accidents of aircraft crashes

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 post-weld heat treatment method for improving the corrosion resistance of aluminum-lithium alloy electron beam welded joints
  • A post-weld heat treatment method for improving the corrosion resistance of aluminum-lithium alloy electron beam welded joints
  • A post-weld heat treatment method for improving the corrosion resistance of aluminum-lithium alloy electron beam welded joints

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] The first step is to select the Al-Cu-Li alloy plate, first use the electron beam process to butt weld it, and then carry out solid solution treatment on the aluminum-lithium alloy electron beam welding head in the air circulation furnace. The process is to weld the aluminum-lithium alloy The electron beam welding head is heated to 510°C, kept for 1h, and water-cooled and quenched;

[0031] In the second step, the welded joint after solution treatment is subjected to aging treatment at 150°C×14h in a blast drying oven;

[0032] In the third step, the welded joint after the first aging treatment is subjected to aging treatment at 160°C×12h in a blast drying oven;

[0033] In the fourth step, the welded joint after the second aging treatment is subjected to aging treatment at 130° C. for 16 hours in a blast drying oven.

[0034] The intergranular corrosion test was carried out on the aluminum-lithium alloy electron beam welded joints after solid solution + three-stage ag...

Embodiment 2

[0038] According to the method of Example 1, the aluminum-lithium alloy electron beam welded joint was subjected to post-weld heat treatment. The exfoliation corrosion (referred to as exfoliation corrosion) test was carried out on the aluminum-lithium alloy electron beam welded joints with post-weld solid solution + three-stage aging treatment to analyze and evaluate the sensitivity of post-weld solid solution + three-stage aging treatment joints to exfoliation, and compared with the welded state The sensitivity of the lower joint to denudation was compared. Exfoliation Corrosion (EXCO) was carried out according to ASTM G 34-2001 standard, and the solution system was EXCO solution (4.0mol L -1 NaCl+0.5mol L -1 KNO 3 +0.1mol·L -1 HNO 3 ), the ratio of solution volume to sample area is 20mL / cm 2 , the test temperature is (25±3)°C, observe intermittently after soaking, and take pictures of the macroscopic appearance of the sample after washing off the corrosion products; com...

Embodiment 3

[0047] According to the method of Example 1, the aluminum-lithium alloy electron beam welded joint was subjected to post-weld heat treatment. According to the method of Example 2, the exfoliation corrosion test was carried out on the aluminum-lithium alloy electron beam welded joint. Analyze and evaluate the sensitivity of post-weld solution + three-stage aging treatment joints to exfoliation corrosion, and carry out post-weld solution + two-stage aging treatment (solution treatment: 510℃×1h, water cooling and quenching; two-stage aging: 160℃ ×16h+130℃×16h) Al-Li alloy electron beam welded joints were compared for exfoliation corrosion sensitivity.

[0048] Figure 4 It is the photo of the exfoliation corrosion morphology of the post-weld solid solution + dual-stage aging treatment joint sample. Table 3 is the rating of the erosion degree of the post-weld solid solution + dual-stage aging treatment joint samples according to the ASTM G34-2001 standard.

[0049] Table 3 Corr...

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
thicknessaaaaaaaaaa
Login to view more

Abstract

The invention discloses a postweld heat treatment method for improving the corrosion resistance of an aluminum-lithium alloy electron beam welded joint. The method comprises the steps that (1) solution treatment is conducted in an air circulation furnace; in the technological process, the aluminum-lithium alloy electron beam welded joint is heated to 510 DEG C for one hour of heat preservation and then is subjected to water hardening; (2) the welded joint subjected to solution treatment is subjected to aging treatment in an air blast drying oven at 150 DEG C for 14 hours; (3) the welded joint subjected to aging treatment for the first time is subjected to aging treatment in the air blast drying oven at 160 DEG C for 12 hours; and (4) the welded joint subjected to aging treatment for the second time is subjected to aging treatment in the air blast drying oven at 130 DEG C for 16 hours. Through postweld solution treatment and the three stages of aging treatment, weld metal of the joint and strengthening phases in a heat-affected zone are fully separated out. The volume fraction of the strengthening phases of a welding zone is increased. Structural grains of the joint zone are refined. The distribution uniformity of a microstructure of the joint zone is improved. The corrosion resistance of the welded joint is improved while the mechanical properties of the joint are greatly improved.

Description

technical field [0001] The invention belongs to the technical field of metal material processing and corrosion protection, and in particular relates to a post-weld heat treatment method for improving the corrosion resistance of an aluminum-lithium alloy electron beam welding joint. Background technique [0002] As a new type of structural material, aluminum-lithium alloy has excellent properties such as high specific strength, high specific modulus, low density and superplasticity. Replacing other aluminum alloy materials with aluminum-lithium alloys can reduce the weight of components by 10% to 15%, and increase the stiffness by 15% to 20%, so it has broad application prospects in aerospace and other fields. In industrial production, aluminum-lithium alloys are mostly used as welded structures. In the welding process of aluminum-lithium alloy, there are disadvantages such as large tendency of welding hot cracks, easy generation of weld pores, and softening of welded joints...

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): C22F1/057C21D9/50
CPCC21D9/50C22F1/057
Inventor 王少刚黄燕
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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