Microstructure of the Dissimilar Materials TIG Welding Joint of Mg-8Li Alloy/Al Alloy

2012 ◽  
Vol 557-559 ◽  
pp. 1358-1363
Author(s):  
Dong Song Yin ◽  
Lu Cai Wang ◽  
Bin Jiang ◽  
Mi Lin Zhang ◽  
Li He Mao ◽  
...  
Keyword(s):  
Base Metal ◽  
Reaction Layer ◽  
Arc Welding ◽  
Weld Zone ◽  
Dissimilar Materials ◽  
Optical Microscope ◽  
Al Alloy ◽  
Alloy Base ◽  
Weld Area ◽  
Equiaxed Grains

Microstructure of electromagnetic pulse tungstic electrode argon arc welding (EMP-TIG) welded Mg/Al dissimilar metal joint is studyed using optical microscope, scanning electron microscope, and X-ray diffraction. The results indicate that gas tungsten arc welding can provide Mg/Al joint with excellent microstructure and performance. The welding region is composed of Mg3Al2 phase, α(Mg), β(Li), and MgAl. The weld zone and the Al alloy base materials are well combined. There are massive MgAl phase dendrites in the weld area, which cause the significantly increase of hardness at weld zone. Near the Mg-8Li alloy base metal side of the weld zone, there exists a layer of 100~ 200μm equiaxed region. About 1μm Mg3Al2 reaction layer is distributed between Mg-8Li alloy base metal and the equiaxed grains. This reaction layer and the Mg-8Li alloy base metal, as well as the weld zone of equiaxed grains, have a good combination.

Gas metal arc welding of XPF800 steel for automotive industry: Microstructural evaluation and mechanical properties investigation

2021 ◽  
pp. 146442072110567
Author(s):  
Emre Korkmaz ◽  
Cemal Meran
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Metal Arc Welding ◽  
Heat Affected Zone Softening

In this study, the effect of gas metal arc welding on the mechanical and microstructure properties of hot-rolled XPF800 steel newly produced by TATA Steel has been investigated. This steel finds its role in the automotive industry as chassis and seating applications. The microstructure transformation during gas metal arc welding has been analyzed using scanning electron microscope, optical microscope, and energy dispersive X-ray spectrometry. Tensile, Charpy impact, and microhardness tests have been implemented to determine the mechanical properties of welded samples. Acceptable welded joints have been obtained using heat input in the range of 0.28–0.46 kJ/mm. It has been found that the base metal hardness of the welded sample is 320 HV0.1. On account of the heat-affected zone softening, the intercritical heat-affected zone hardness values have diminished ∼20% compared to base metal.

Microstructure Characteristic of AZ31/7005 Joints by GTAW with Filler Wire of Mg-Al Alloy

2014 ◽  
Vol 1004-1005 ◽  
pp. 168-171
Author(s):  
Hong Yan Du ◽  
Yaj Jang Li ◽  
Juan Wang
Keyword(s):  
Solid Solution ◽  
Intermetallic Compounds ◽  
Fusion Zone ◽  
Weld Zone ◽  
Dissimilar Materials ◽  
Eutectic Structure ◽  
Al Alloy ◽  
Test Results ◽  
Al Content ◽  
Mg Content

Mg/Al dissimilar materials were welded successfully by GTAW with SAlMg-1 and SAlMg-2 welding wire of Mg-Al system. The nice weld shape and free defects of joints are obtained. The test results indicated that continuous lamellar intermetallic compounds is not found The structure of Mg side in the fusion zone is composed of α-Mg solid solution+ β-Al12Mg17eutectic structure and precipitates β-A112lMg17on the grain boundary. The structure in the weld zone is mainly α-Mg solid solution + β-A112lMg17solid solutions. Mg and Al content are stable in the fusion zone of Mg side. However, in the weld zone of Mg side the Mg content is decreased gradually, and the Al content is increased that reaches a stable level in the weld zone of Al side. As a result, when Mg content in the wire can hold a proper level, the intermetallic compounds will be controlled effectively, and the performance of AZ31/7005 welding joint can be improved.

Effects of Filler Compositions on Mechanical and Physical Properties of the Dissimilar Resistance Spot Welded between Aluminium Alloy and Carbon Steel

2015 ◽  
Vol 656-657 ◽  
pp. 422-427
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Muhammad Fathan
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Physical Properties ◽  
Aluminium Alloy ◽  
Base Metal ◽  
Testing Machine ◽  
Optical Microscope ◽  
Filler Materials ◽  
Al Alloy ◽  
Resistance Spot

The resistance spot weld (RSW) of dissimilar materials betweeen steel and aluminium is generally more complex than that of similar materials due to the extreme differences in the mechanical, physical and chemical properties of the base metals. This study proposed the use of filler material to connect the differences of their properties. Al-Alloy 5083 with thickness of 4 mm and 1.2 mm thick carbon steel SS400 were joined in lap joint types using RSW with the filler materials. The filler materials were a mixture of steel and aluminium in which weight composition variations (Fe:Al) were 90:10; 70:30; 30:70 and 90:10 in percent. The physical properties were examined based on the microstructure using optical microscope while the mechanical properties were measured with respect to the strength and hardness using Universal Testing Machine and Vickers Microhardness respectively. Results showed that weld metals with filler composition of 70:30% had highest shear-strength. The microstructure examinations showed that Microstructure of base metal and HAZ carbon steel was ferrite and perlite while that of weld metal was bainite. There were no significant differences in the microstructures and the hardness of weld metal, HAZ, and the base metal of aluminium alloy-5083 due to nonheat-treatable material.

Microstructure and Properties of Mg/Al Dissimilar Joints by GTAW with Al-Si Filler Wire

2014 ◽  
Vol 941-944 ◽  
pp. 2035-2038
Author(s):  
Hong Yan Du ◽  
Ya Jiang Li ◽  
Juan Wang
Keyword(s):  
Fusion Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Dissimilar Materials ◽  
High Hardness ◽  
Optical Microscope ◽  
Columnar Structure ◽  
Test Results ◽  
Dissimilar Joints ◽  
Brittle Phase

Mg/Al dissimilar materials were welded successfully by GTAW with SAlSi welding wire of Al-Si system. The nice surface forming and free defects of joints are formed. Mg/Al welded joint were tested and analyzed by means of optical microscope, scanning electron microscope, microhardness tester. The test results show that in the fusion zone of Mg side, it shows the intense columnar crystalline structure and little intergranular precipitates, and has more dendritic intergranular precipitates. However, the weld zone shows the typical columnar structure zone. There is no high hardness brittle phase in fusion zone of Mg side. The hardness of weld zone is slightly higher than one of Mg substrate, and far less than the Al substrate.

scholarly journals Analisis Kekerasan Hasil Pengelasan Gas Tungsten Arc Welding pada Baja ST 37 dengan Variasi Media Pendingin

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Gede Agus Widiantara ◽  
I Nyoman Pasek Nugraha ◽  
Kadek Rihendra Dantes
Keyword(s):  
Base Metal ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Water Cooling ◽  
Gas Tungsten Arc ◽  
A Value ◽  
Gas Tungsten ◽  
Cooling Media ◽  
Weld Area ◽  
Hardness Values

Cooling media is a substance that increases the hardness value of a materialthrough a heat-treatment process. This study aims to determine the effect of cooling media on the hardness of ST 37 steel due to Gas Tungsten Arc Welding (GTAW). The method used is an experimental method using the independent variables, namely water cooling media, seawater cooling media, and oil cooling media, while the dependent variable is the hardness test result. In specimens using water cooling media, the hardness in the weld area is 47.19 kg/mm2, in the HAZ area the it is 54.6 kg/mm2, and the base metal gets a value of 40.87 kg/mm2. While the specimens with seawater cooling media get a value in the weld area of 76.37 kg/mm2, in the HAZ area it gets a value of 83.89 kg/mm2 and the base metal gets a value of 70.13 kg/mm2. The specimens with oil cooling media the value in the weld area is 40.77 kg/mm2, in the HAZ area it gets a value of 43.32 kg/mm2 and the base metal gets a value of 36.09 kg/mm2 . From the hardness values obtained, specimens immersed in seawater cooling media have the highest hardness values compared to water and oil cooling media.

Experimental investigation of structural integrity behavior of High strength low alloy steel – Study of mechanical, microstructural and corrosion behavior of Submerged arc welding weldments

2020 ◽  
pp. 095440892095810
Author(s):  
Lochan Sharma ◽  
Rahul Chhibber
Keyword(s):  
Corrosion Resistance ◽  
Impact Strength ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Welding Fluxes ◽  
Submerged Arc ◽  
Metal Impact

The present study aims at investigating the effect of submerged arc welding fluxes for enhanced corrosion resistance of structural steel welds. By varying the basicity index of submerged arc welding fluxes the corrosion resistance and mechanical properties of weld metal such as tensile strength, impact strength, microhardness in submerged arc weldments were evaluated. The result shows that with the increase in bascity index tensile strength of weld specimen reduced while impact strength and microhardness value increased. Maximum microhardness (288 HV) was observed for flux 2 while base metal show minimum microhardness value (205 HV). Flux 5 gives maximum impact strength (94.17 J) as compared to the base metal (80 J). This is due to the reduced content of oxygen in weld metal which increases the weld metal impact toughness. Corrosion resistance of weld specimen increased as compared to the base metal. Ductile fracture mode and shear lip or tears were observed in the weld zone. Shear dimples and shear lips were more severe in base metal as well as weld metal impact specimens due to the rapid effect of external forces on the impact test. The banded microstructure of delta ferrite and austenite was observed in the base metal. Fine grains of ferrite and pearlite at the center and edges were present in the weld zone.

Effect of PWHT on Behaviors of Precipitates and Hardness Distribution of 6061 Al Alloy Joints by Friction Stir Welding Method

2004 ◽  
Vol 449-452 ◽  
pp. 601-604 ◽  
Author(s):  
Won Bae Lee ◽  
Hyung Sun Jang ◽  
Yun Mo Yeon ◽  
Seung Boo Jung
Keyword(s):  
Friction Stir Welding ◽  
Base Metal ◽  
Dynamic Recovery ◽  
Weld Zone ◽  
Frictional Heat ◽  
Al Alloy ◽  
Hardness Distribution ◽  
Friction Stir ◽  
Heat Treated ◽  
6061 Al Alloy

The hardness distribution related to the precipitates behaviors as friction stir welded and PWHT (post weld heat treated) 6061 Al alloy have been investigated. Frictional heat and plastic flow during friction stir welding created a fine, eqiuaxed and elongated microstructure near the weld zone due to dynamic recovery and recrystallization. A softened region which had been formed near the weld zone couldn't be avoidable due to the dissolution and coarsening of the strengthening precipitates. PWHT (SHT+ Aging) homogeneously recovered the hardness distribution over that of the base metal without softening region, resulted from non-homogeneously distributed hardness only aging treated. 36ks aging followed by SHT gave a higher hardness overall weld than that of the base metal due to a higher density of the spherical shaped precipitate.;

A Study on the SCC Susceptibility of Twin-Wire Metal Inert Gas Arc Welds in 7A52 Al Alloy Plate

2011 ◽  
Vol 311-313 ◽  
pp. 619-623
Author(s):  
Xiao Dong Wang ◽  
Rui Ling Jia ◽  
Hui Xia Zhang ◽  
Hua Jian Lui ◽  
Xi Wei Zhai ◽  
...  
Keyword(s):  
Arc Welding ◽  
Electrochemical Impedance ◽  
Weld Zone ◽  
Electrochemical Corrosion ◽  
Parent Material ◽  
Test Method ◽  
Inert Gas ◽  
Al Alloy ◽  
Alloy Plate ◽  
Electrochemical Corrosion Behavior

7A52 Al alloy plates was welded using twin-wire metal inert gas arc welding (TMW) .Stress corrosion cracking (SCC)behavior of the parent material and the welded specimens was investigated by the slow strain rate tensile(SSRT)test method respectively. Electrochemical impedance spectroscopy (EIS) was conducted to understand electrochemical corrosion behavior of 7A52 Al alloy and its TMW weldment. It was found that the welded specimens exhibited higher SCC susceptibility than the parent materials under SSRT testing in seawater. The EIS result showed that the weld zone exhibited higher corrosion resistance than that of the parent material. Hydrogen embrittlement is a crucial factor that leads to the failure of the welded specimens during SSRT test in seawater.

Effects of Root Opening on Physical and Mechanical Properties of the Double Side Welded of Ship Materials

2016 ◽  
Vol 835 ◽  
pp. 167-172
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Tegar Rileh Argihono ◽  
Ryan Sutrisno
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Gas Metal Arc Welding ◽  
Weld Zone ◽  
Physical And Mechanical Properties ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Optical Microscope ◽  
Weld Metals

The effects of root opening process parameters on the phisical and mechanical properties of mild steel specimens of grade LR Gr A having dimensions 200 mm× 100 mm× 12 mm, welded by gas metal arc welding were investigated. The variation of root opening that used were 3 mm, 5 mm and 7 mm. The physical properties examined with regard with microstructure, macrosructure, and corrosion using optical microscope and stereozoom. The measured of mechanical properties with regard to strength, hardness and toughness using, tensile test, Vickers hardness Test, and Charpy impact test. The test results show the base metal had a hardness of approximately 110 VHN and a maximum hardness of approximately 190 VHN that corellates with microstructure of weld metals. Microstructure of base metal and HAZ are ferite and perlite, while microstructure of weld zone are acicular ferrite and grain boundary ferrite. The corrosion rate of weld metals with various root opening categorized as materials having excellent corrosion resistance value. Welding joints with opening roots 3 mm and 5 mm can be used for construction. All welded specimens exhibited fracture at base metals

Macro/Micro Mechanical Level Characterization of Spot Friction Welded Lap Joints in 6111 Aluminum Alloy Using Combined Experimental/Numerical Approaches

2007 ◽  
Author(s):  
Srinivasa D. Thoppul ◽  
Ronald F. Gibson
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Processing Time ◽  
Weld Zone ◽  
Lap Joints ◽  
Processing Times ◽  
Lap Shear ◽  
Apparent Stiffness ◽  
Alloy Base ◽  
Numerical Finite Element

Modal vibration testing and static flexure testing at the macromechanical level combined with numerical finite element (FE) models have been used to indirectly determine the elastic moduli of 6111 aluminum alloy base metal and spot friction welded (SFW) joints which have been formed at different processing times. It was observed that the frequency (and the corresponding apparent stiffness) of the joint oscillates at low amplitudes as processing time increases. For each vibration mode, the amplitude of the oscillation in the frequency vs. processing time is only a few percent of the mean frequency with 99% confidence level, while the corresponding lap shear strength increases monotonically by a factor of about 8 as the processing time increases. Due to the scatter in the damping data it is difficult to detect any significant trends. Comparison of predicted modal frequencies and static load-displacement response of SFW joints at the macromechanical level with the corresponding measured responses seems to indicate that the weld zone is not as stiff as the base metal, but more detailed micromechanical analysis is required before definite conclusions can be drawn. In addition, studies of microstructural characteristics and Vickers microhardness distributions across the weld zone for the SFW samples reveals the formation of a partial metallurgical bond in the direction of flow, which is governed by the tool used, whereas the hardness distribution in the weld zone depends on the processing time.

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