Research on corrosion behavior of A6N01S-T5 aluminum alloy welded joint for high-speed trains

Aluminum alloy components of high-speed trains have a great risk of being corroded by various corrosive medium due to extremely complex atmospheric environments. This will bring out huge losses and reduce the safety and stability of trains. In order to solve the problem, cold spray process was used for repairing the damage of the aluminum alloy components with Al-based powders. Microstructure, mechanical properties and corrosion behavior were studied. The results indicated that there were very few pores and cracks in the repaired areas after repairing. The average microhardness of the repaired areas was 54.5 HV ± 3.4 HV, and the tensile strength of the repaired samples was 160.4 MPa. After neutral salt spray tests for 1000 h, the rate of mass loss of the samples repaired by cold spray was lower than that of 6A01 aluminum alloy. The electrochemical test results showed that the repaired areas had a higher open circuit potential than 6A01 aluminum alloy. As a result, the repaired areas such as the anode protected its nearby substrate. The samples repaired by cold spray exhibited better corrosion than 6A01 aluminum alloy. Cold spray process and Al-based powders are applicable for repairing the aluminum alloy components of high-speed trains.

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Research on Salt Fog Corrosion Behavior of Welded Joint of 7N01-T4 Aluminum Alloy for High-Speed Train

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2822 ◽

2011 ◽

Vol 239-242 ◽

pp. 2822-2826 ◽

Cited By ~ 4

Author(s):

Xiao Min Wang ◽

Jun Jing Zhao ◽

Guo Qing Gou

Keyword(s):

Aluminum Alloy ◽

Corrosion Behavior ◽

High Speed ◽

Welded Joint ◽

High Speed Train ◽

Welding Seam ◽

Corrosion Zone ◽

Micro Morphology ◽

Salt Fog Corrosion ◽

Salt Fog

Salt fog corrosion test was employed to observe the corrosion behavior of welded joint of 7N01-T4 aluminum alloy of high-speed train. Tensile strength and hardness change after corrosion were tested and micro morphology was observed by metalloscope and LCSM. The results indicated that HAZ was the most sensitive corrosion zone in welded joint of 7N01-T4 in chlorinated moisture environment. Influenced by the heat-input of welding, the grains of HAZ were coarsening and inhomogeneous. A corrosion cell between welding seam with high Mg content and HAZ with high Zn content formed. HAZ corroded preferentially as anode, and the dissolving of zinc-rich phase in grain boundary resulted in the extending of corrosion crack along grain boundaries.

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Elements loss analysis based on spectral diagnosis in laser-arc hybrid welding of aluminum alloy

International Journal of Modern Physics B ◽

10.1142/s0217979217440362 ◽

2017 ◽

Vol 31 (16-19) ◽

pp. 1744036

Author(s):

Yong Chen ◽

Hui Chen ◽

Minhao Zhu ◽

Tao Yang ◽

Lin Shen

Keyword(s):

Aluminum Alloy ◽

High Speed ◽

Welding Process ◽

Spectral Intensity ◽

Hybrid Welding ◽

Loss Analysis ◽

Welding Defects ◽

High Speed Trains ◽

Arc Current ◽

Weld Area

Aluminum alloy has been widely used in automobiles, high-speed trains, aerospace and many other fields. The loss of elements during welding process causes welding defects and affects the microstructure and properties of the joints. This paper discusses the correlation between welding process, spectral intensity and loss of elements in laser-arc hybrid welding of Al alloys. The results show that laser power and arc current have a significant impact on the spectral intensity and loss of elements. Compared with the base metal, the contents of alloying elements in the weld area are lower. The burning losses of alloy elements increase with the welding heat input.

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Corrosion Behavior of SMA490BW Steel and Welded Joints for High-Speed Trains in Atmospheric Environments

Materials ◽

10.3390/ma12183043 ◽

2019 ◽

Vol 12 (18) ◽

pp. 3043 ◽

Cited By ~ 1

Author(s):

Xiangyang Wu ◽

Zhiyi Zhang ◽

Weichuang Qi ◽

Renyong Tian ◽

Shiming Huang ◽

...

Keyword(s):

Weight Loss ◽

Corrosion Behavior ◽

Welded Joints ◽

Corrosion Test ◽

High Speed ◽

Loss Rate ◽

Corrosion Potential ◽

Weight Loss Rate ◽

Cyclic Corrosion ◽

High Speed Trains

Currently, high-speed trains work under various atmospheric environments, and the bogie as a key component suffers serious corrosion. To investigate the corrosion behavior of bogies in industrial atmospheric environments, the periodic immersion wet/dry cyclic corrosion test for SMA490BW steel and automatic metal active gas (MAG) welded joints used for bogies was conducted in the present work. Corrosion weight loss rate, structure, and composition of rust layers as well as electrochemistry parameters were investigated. The results showed that the corrosion weight loss rate decreased with increasing corrosion time; furthermore, the corrosion weight loss rate of the welded joints was lower than that of SMA490BW steel. The XRD results showed that the rust layers formed on SMA490BW steel and its welded joints were mainly composed of α-FeOOH, γ-FeOOH, Fe2O3, and Fe3O4. The observation of surface morphology indicated that the rust layers of the welded joints were much denser and had a much finer microstructure compared with those of SMA490BW steel. After corrosion for 150 h, the corrosion potential of the welded joints with rust layers was higher than that of SMA490BW steel. In short, the welded joints exhibited better corrosion resistance than SMA490BW steel because of the higher content of alloy elements, as shown in this work.

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Study on the AZ31B Magnesium Alloy in the Application on High-Speed Trains

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.875 ◽

2012 ◽

Vol 535-537 ◽

pp. 875-879 ◽

Cited By ~ 1

Author(s):

Jia Zhen Liu ◽

Yan Hui Zhao ◽

Lei Song ◽

Zhong Xia Xiang

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Magnesium Alloy ◽

High Speed ◽

Equivalent Stress ◽

Strength Analysis ◽

Az31b Magnesium Alloy ◽

High Speed Trains ◽

6063 Aluminum Alloy ◽

The Impact

6063 aluminum alloys are used as the luggage rack’s material on high-speed trains recently. The study on the AZ31B magnesium alloy is aimed to demonstrate the feasibility of the magnesium alloy’s application as the material of the luggage rack on high-speed trains. First, the mechanical properties of the AZ31B magnesium was obtained after a series of experimental tests on basic mechanical properties of the AZ31B magnesium alloy. The results show that the strength of the magnesium alloy is 1.25 times of the 6063 aluminum alloy and the impact toughness of the AZ31B magnesium alloy is twice as much as the 6063 aluminum alloy. Second, the stress distribution and the maximum value of the equivalent stress in given loading conditions was obtained by finite element strength analysis on the structure of the aluminum alloy luggage rack on high-speed trains. And the FE analysis results indicate that if the AZ31B magnesium alloy is used as the material of the luggage rack instead of the 6063 aluminum alloy, it will have a weight loss of the luggage rack for approximately 33%. In addition, the application of AZ31B magnesium alloy has more advantages in energy-saving, environmental protection and safety control.

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Corrosion behavior of refilled friction stir spot welded joint between aluminum alloy and galvanized steel

Materials Research Express ◽

10.1088/2053-1591/aad890 ◽

2018 ◽

Vol 5 (9) ◽

pp. 096524

Author(s):

Peng Li ◽

Yaqiang Wang ◽

Shuai Wang ◽

Jiang Yang ◽

Honggang Dong ◽

...

Keyword(s):

Aluminum Alloy ◽

Corrosion Behavior ◽

Welded Joint ◽

Galvanized Steel ◽

Friction Stir ◽

Spot Welded

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The corrosion behavior of marine aluminum alloy MIG welded joints in a simulated tropical marine atmosphere

Materials Testing ◽

10.1515/mt-2020-0027 ◽

2021 ◽

Vol 63 (2) ◽

pp. 151-156

Author(s):

Lihua Gong ◽

Weimin Guo ◽

Feng Pan

Keyword(s):

Aluminum Alloy ◽

Corrosion Rate ◽

Base Metal ◽

Corrosion Behavior ◽

Welded Joint ◽

Salt Spray ◽

Atmospheric Environment ◽

Cycle Period ◽

Corrosion Tests ◽

Immersion Corrosion

Abstract The influence of metal inert-gas arc welding (MIG) on the corrosion behavior of 6061-T6 aluminum alloy in a simulated tropical marine atmospheric environment (related to high temperature, high humidity and high salt spray) were examined by dry-wet alternate immersion corrosion tests. The equivalent conversion was used to design the accelerated test time. The results show that in the initial stage, the intermetallic compound, rich in Fe, Si and Cu, had little influence on corrosion resistance in the heat-affected zone. For a corrosion time of 3 days in a tropical marine atmospheric environment, the corrosion rate of the welded joint increased rapidly, even reaching 3.5 times that of the base metal. Though the corrosion products had significant impact on slowing down the corrosion rate, as with the base metal, the corrosion rate of the welded joint was nearly double that of the base metal during the longest cycle period involving alternate immersion corrosion tests for 20 days.

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Effect of sand-blasting on fatigue properties of 7N01 aluminum alloy

International Journal of Modern Physics B ◽

10.1142/s0217979219400034 ◽

2019 ◽

Vol 33 (01n03) ◽

pp. 1940003 ◽

Cited By ~ 1

Author(s):

Shali Qu ◽

Min Yu

Keyword(s):

Residual Stress ◽

Aluminum Alloy ◽

Fatigue Life ◽

High Speed ◽

Fatigue Properties ◽

Sand Particle ◽

Surface Zone ◽

Sand Blasting ◽

Depth Direction ◽

High Speed Trains

Certain high-speed trains often suffer from the erosion of wind-drift sand during the serving period. The present paper simulated this sand-blasting process with consideration of sand-blasting pressure, angle, distance and sand particle size representing different natural conditions. Results show that the grit size has the greatest influence on roughness and residual stress of the 7N01 aluminum alloy based on the orthogonal test. The samples after low intensity sand-blasting (LISB) were characterized by micro-hardness, surface morphology and fatigue test. Results show that the surface of the blasted sample was severely impinged in form of extruded ridges crater-like morphology, representing different roughness values. The LISB causes a similar spoon shape residual stress distribution along the depth direction and it also increases the hardness of the surface zone. Finally, the residual compressive stress plays an important role in the improvement of the fatigue life, and the increase of roughness can seriously shorten the fatigue life.

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