Study of metallurgical changes and mechanical properties of dissimilar weldments developed by interpulse current TIG welding technique

2020 ◽  
pp. 095440622096078 ◽  
Author(s):  
Balram Yelamasetti ◽  
T Vishnu Vardhan ◽  
G Venkat Ramana
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Weld Zone ◽  
Welding Process ◽  
Tig Welding ◽  
Weld Strength ◽  
Austenitic Phase ◽  
Monel 400 ◽  
Electron Microscopes ◽  
Metallurgical Study

This research manuscript compares the metallurgical changes and mechanical behavior of AISI 316 and Monel 400 dissimilar weldments developed by Interpulse TIG welding process with ERNiCrMo-3 and ER316 filler wires. Metallurgical aspects are envisioned by using optical and scanning electron microscopes. Mechanical behavior of welded joints were studied by conducting tensile and microhardness tests. Metallurgical study has shown that the ERNiCrMo-3 filler weldment divulged completely with austenitic phase structure at the weld zone. Also, at the HAZ of Monel 400 clear grain boundaries with fine grains were observed. The mechanical properties corroborated that the weld strength of ERNiCrMo-3 weldment was found better than the ER316 weldment. Microhardness on the weldment made of ERNiCrMo-3 filler has shown higher values than that of base metals. Weldment made by ER316 was observed to fail near the interface of Monel 400 under tensile test due to the existence of micro-pores and partially melted zones. Further, the metallurgical and mechanical properties are compared with that of the weldment developed by TIG welding process.

Effects of bottom plate in friction stir welding of AA6061-T6

2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Axial Load ◽  
Weld Zone ◽  
Welding Process ◽  
Bottom Plate ◽  
Welding Parameters ◽  
Nugget Zone ◽  
Friction Stir ◽  
Weld Joints ◽  
Fine Grain

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.

Investigation on the effects of the joint type on the driven out bead in the welded pipes produced by high-frequency induction welding

2020 ◽  
pp. 146442072097343
Author(s):  
M Ghaffarpour ◽  
D Akbari ◽  
H Moslemi Naeini
Keyword(s):  
Mechanical Properties ◽  
Weld Joint ◽  
High Frequency ◽  
Weld Zone ◽  
Welding Process ◽  
Solid Material ◽  
Outer Diameter ◽  
Metallurgical Properties ◽  
Semi Solid ◽  
High Frequency Induction

In this paper, the effects of the joint type on the driven-out bead of the roll-formed pipes, welded by high-frequency induction welding process are studied. The main goal is to predict and reduce the volume of the bead driven out in the weld seam. Moreover, it aims to move the semi-solid bead during welding to the outer diameter of the pipe. This study has two prior aims: to produce a defect-free joint and to improve the mechanical and metallurgical properties. In order to optimize the weld joint, various joint types have been investigated by experimental tests and simulation. Lastly, destructive tests were used to determine if the desired mechanical properties of the weld joint were obtained. The metallurgical properties and the derivation of the semi-solid material in the weld zone have both been investigated in terms of microstructure. According to the results, the proper joint type improves the mechanical properties by 5% and reduces the volume of the weld bead about 45%.

A Case Study of Gas Leakage and Assessment of Mechanical Properties With Welding Variables in Fillet Weldment of Small Diameter Pipe

2006 ◽  
Author(s):  
Jong-Hyun Baek ◽  
Woo-Sik Kim
Keyword(s):  
Mechanical Properties ◽  
Fatigue Strength ◽  
Natural Gas ◽  
Weld Zone ◽  
Branch Pipe ◽  
Small Diameter ◽  
Welding Process ◽  
Pipe Diameter ◽  
Pipe Material ◽  
Gas Leakage

A branched pipe joint has been employed to execute the pressure control, condition check, purgation, and distribution of the gas in the natural gas facilities. Installation of branch pipes is generally done through the welding work, and as a welding process, the weldolet and the sockolet are used. During the maintenance working of in-service natural gas pipeline, there was gas leakage in sockolet weldment. The causes of incident were investigated with various tests. We found the wrong pipe material, the weld defect and the non-destructive test limitation of fillet weldment as the reasons of gas leakage. As the follow-up measures, it was done to assess the soundness depending upon the configuration of the weld zone, a change in the welding process and a change in the pipe diameter by assessing the mechanical properties of the sockolet weld zone and further to assess comparatively the mechanical performance of the sockolet weld zone and that of the weldolet weld zone. In the sockolet weld, the tensile strength showed no difference and the fatigue strength showed a difference depending upon a change in the welding process. In the case that the leg length of the weld zone was made lengthwise in the direction of the branch pipe, the SMAW welding work compare with the GTAW, the sectional area of the weld zone was more increased, and the pipe diameter was more increased, the fatigue strength was increased.

Studies on cold metal transfer welding of aluminium alloy 6061-T6 using ER 4043

2020 ◽  
Vol 234 (7) ◽  
pp. 924-937
Author(s):  
R Pramod ◽  
N Siva Shanmugam ◽  
CK Krishnadasan
Keyword(s):  
Mechanical Properties ◽  
Aluminium Alloy ◽  
Pressure Vessel ◽  
Weld Zone ◽  
Welding Process ◽  
Metal Transfer ◽  
Welding Parameter ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Alloy 6061

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.

scholarly journals A Study on Vertical Upward Welding of Dissimilar Material and Thickness of Thin Plates Using Novel TIG Welding Process

2019 ◽  
Author(s):  
Ngo Huu Manh ◽  
Nguyen Van Anh ◽  
Murata Akihisa ◽  
Hideno Terasaki
Keyword(s):  
Base Metal ◽  
Heat Input ◽  
Weld Zone ◽  
Welding Process ◽  
Welding Current ◽  
Tig Welding ◽  
Dissimilar Material ◽  
Thin Plates ◽  
Welding Defects ◽  
Welding Position

A study about influence of heat input on welding defects in vertical upward welding position for dissimilar material and thickness using a new variation of TIG welding torch is done with support of advanced inspection methods SEM and EBSD. With vertical upward welding position, control heat input plays an important role to keep the weld stabilization without defects. On the other hand, TIG welding process using a conventional TIG torch (conventional TIG welding process) has low efficiency and it is difficult to control heat input with high accuracy. So, it is considered that using conventional TIG torch is still a challenge for welding thin plates. In this case, a new variation of TIG torch has been developed. This torch used a constricted nozzle to improve plasma arc characteristics. As a result, it can control efficiently the heat input to prevent the excessive or insufficiency for joining thin sheets. For evaluation of welding quality, advanced examination methods SEM and EBSD were applied to directly observe the welding defects. From the results, the formation mechanism of blowhole inside weld zone in case of welding dissimilar material and thickness was discussed. It is pointed out that when sufficient welding current, the change from weld zone to base metal is uniform, no welding defects such as blowhole was seen. However, in case of low welding current, the thinner base metal is insufficient fusion and the change between weld zone and base metal is not uniform. The blowhole was observed at SS400 material side.

Welding Repair of Aluminium Alloy 6082 T6 by TIG Welding Process

2016 ◽  
Vol 872 ◽  
pp. 3-7
Author(s):  
Kraiwut Hoyingchareon ◽  
Prapas Muangjunburee
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Aluminium Alloy ◽  
Flow Rate ◽  
Heat Affected Zone ◽  
Gas Flow ◽  
Welding Process ◽  
Tig Welding ◽  
Gas Flow Rate ◽  
Complete Melting

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.

Sign in / Sign up

Export Citation Format

Share Document