Improvement of Welding Repair Aluminium Alloy 6082T6 by MIG Welding Process

2016 ◽  
Vol 872 ◽  
pp. 8-12
Author(s):  
Nitipon Nimaeh ◽  
Prapas Muangjunburee

The repair welding of aluminium alloy 6082T6 with two fillers 4043 and 5356 were studied by using MIG welding process with pulse current at frequency 5 Hz. After that, macrostructure and microstructure were investigated and the density of porosity and testing of mechanical properties were determined. The results found that the density of new weld was less than repair weld. The results of mechanical tests showed that the new weld were better than the repair weld.

2006 ◽  
Vol 321-323 ◽  
pp. 1733-1737 ◽  
Author(s):  
Seung Wan Woo ◽  
Choon Yeol Lee ◽  
Jae Do Kwon ◽  
Young Hwan Choi ◽  
Ho Sang Shin

Conventionally, shielded-metal arc welding (SMAW) process has been applied to join pipes of reactor coolant loop, which caused defects and lot of loss in time and cost due to excessive heat input in joining section. Recently, narrow-gap welding (NGW) process was introduced to overcome the disadvantages of SMAW. However, the application of NGW to nuclear power plant is not yet commonly used, because safety of NGW process is not fully proven. In the present paper, welded coupons are made of stainless steel. They are manufactured under different processes; general welding (GW), and repair welding after GW. Performed are various mechanical tests to investigate microstructure, tensile strength and so on. It is verified that the mechanical properties of stainless steel are slightly changed after repair welding process. It is also found from stress corrosion cracking tests that the failure time of repair welding is shorter than that of general welding.


Author(s):  
R Pramod ◽  
N Siva Shanmugam ◽  
CK Krishnadasan

Aluminium alloy 6061-T6 is utilized in aerospace industry for developing pressure vessel liner. Cold metal transfer is a promising welding process used in fabricating aluminium structures. The present work is focussed to achieve an optimum welding parameter for joining a 3.5-mm thick pressure vessel and to examine the mechanical properties and metallurgical nature of the weldment. The welded joint was evaluated as defect free using radiography test. The joint efficiency (66.61%) and measured microhardness of weldment (59.78 HV) exhibited promising results. The effect of grain coarsening in the heat affected zone (HAZ) and weld zone is attributed to the thermal gradients during welding. Dissipation of small amounts of strengthening elements Si and Mg during welding leads to reduction in mechanical properties. X-ray diffraction peaks revealed the presence of intermetallic Al–Si and Fe–Si in the weld zone. Fractography examination confirms the ductile type of failure in the fractured surface of the tensile samples.


2017 ◽  
Vol 750 ◽  
pp. 26-33
Author(s):  
Alaa Abu Harb ◽  
Ion Ciuca ◽  
Robert Ciocoiu ◽  
Mihai Vasile ◽  
Adrian Bibis ◽  
...  

The welding technique used for ASIS 304 and 316L austenitic stainless steel sheets both with a thickness of 3mm is gas tungsten arc welding (TIG) and manual metal arc welding (MMAW). Mechanical properties that were verified include: hardness test and tensile test before welding and after it. The welding process was done on two types of specimens: with a central hole and without hole. We concluded that there was a decrease in the properties of tensile for both specimens with central hole, and 316L had tensile characteristics better than 304 when using the technique TIG. As for 304, it had tensile characteristics better than 316L when using the technique MMAW. We also concluded that the existence of central holes had an influence on the hardness characteristics on both types. The hardness increased in 304 but decreased in 316L. The welding process also showed that there was no influence of MMAW on hardness on both specimens. However it showed that there was no influence of TIG on the hardness for 304, but for 316L values increased.


2021 ◽  
Vol 23 (2) ◽  
pp. 147-152
Author(s):  
M. D. Shittu ◽  
A. E. Olaniyi ◽  
A. A. Daniyan ◽  
D. A Isadare ◽  
K. M. Oluwasegun ◽  
...  

This paper investigated the effect of magnesium as a dispersion strengthening material on some mechanical properties of 1200-Aluminium (Al-Fe-Si) alloy, a typical commercial aluminium alloy used in the production of household utensils. 1200-Aluminium (Al-Fe-Si) alloy containing varying percentages of the dispersion hardening material (i.e. Magnesium) were produced and mechanical tests namely; hardness, tensile strength and impact strength were carried out. Also, the microstructures of the cast materials were studied. The results showed that increase in magnesium content, as dispersion hardening material improved the hardness, tensile strength and caused a slight decrease in impact strength of the 1200-Aluminium alloy. It is inferred from this work that using magnesium as a dispersion hardening material brings about corresponding improvement in some mechanical properties of 1200-Aluminium (Al-Fe-Si) alloy. Keywords: Magnesium, Aluminium alloy, dispersion strengthened, reinforced alloy, crystallographic formation Depth, Geothermal Energy


2016 ◽  
Vol 872 ◽  
pp. 3-7
Author(s):  
Kraiwut Hoyingchareon ◽  
Prapas Muangjunburee

This work focuses on welding repair of aluminium alloy 6082 T6 by TIG welding process. Two types of filler, 4043 and 5356 were used. A comparison at I= 120A,140A, welding speed 20cm/min and gas flow rate 15 L/min was studied. Physical characteristics, macrostructure and microstructure at weld metal and Heat Affected Zone (HAZ) were investigated. Which at 140A can welding repair. The parameter 140A have complete melting and fail area at HAZ and mechanical properties more than 120A.


2020 ◽  
Vol 8 (5) ◽  
pp. 4727-4732

Aluminium and its alloy has very wide area of application i.e. aerospace, automobile and structural industries. The present investigation aimed to study the effect of MIG welding on microstructural and mechanical properties of AA6061 aluminium alloy. The characteristics of fusion zone is typical coarse columnar grains structure because of the prevailing thermal conditions during weld metal solidification. In this work, plates of 5mm thickness have been used as the base material for preparing single pass butt welded joints at different-different current values. The filler wire used for joining the plates is AA4043 (Al-5%Si by wt.) grade aluminium alloy. From this investigation, it was found that the hardness of fusion zone was degraded significantly due to usage of lower hardness filler metal. The precipitation evolution in the heat-affected zone was characterized by XRD which improves the tensile properties of the welded AA6061 alloy.


2011 ◽  
Vol 295-297 ◽  
pp. 1933-1937 ◽  
Author(s):  
Zhao Dong Zhang ◽  
Xiang Yu Kong

In this paper, the features of weld formation, porosity, arc behavior, microstructure and mechanical properties of 6061 Al alloy thin sheet welds by direct current (DC) double pulse metal inert gas (MIG) welding process are investigated and compared with the traditional DC MIG welding process. Results show that continuous one-side welding with back forming weld beads without spatters, undercuts or cracks can be obtained by using the DC double pulse MIG welding process. The porosity of weld bead can be largely reduced by using the process. The arc of DC double pulse MIG welding is stable without arc blowout, and the metal transfer model of DC double pulse MIG welding is better than that of DC MIG welding. Microstructure of the weld bead by DC double pulse MIG welding shows a dendrite structure and it is fine and uniform. The average ultimate tensile strength and elongation of the weld bead by DC double pulse MIG welding can get to 228MPa, 80% of base metal, and 7.6%, 63% of base metal.


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