scholarly journals Load Controlled Fatigue Behaviour of Microplasma Arc Welded Thin Titanium Grade 5 (6Al-4V) Sheets

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5128
Author(s):  
Jaroslaw Szusta ◽  
Nail Tüzün ◽  
Özler Karakaş
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Experimental Studies ◽  
Welding Process ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Metal Fatigue ◽  
Grade 5 ◽  
Titanium Grade ◽  
Weld Area

The current study investigates the load controlled fatigue properties of the microplasma arc welded thin titanium Grade 5 (6Al-4V) sheets. In order to explore the effect of weld geometry on the fatigue, two different welded joints were used in the experimental studies. Load controlled fatigue test results were evaluated to present an outlook on the behaviour of microplasma welded titanium alloy Grade 5 sheets under cyclic loading. Even though the previously published monotonic tests showed successful use of microplasma arc welding to join thin titanium Grade 5 sheets with mechanical properties comparable to the base metal, fatigue life of the welded joints was lower than the lives of samples without welds. In particular, the fatigue performance of overlap joints was very poor. This was presumed to be due to the changed material properties of the heat affected zone which was formed by the excess heat of the welding process as fractures often occurred at such locations. Based on experimental findings and fractographic observations, a clear adverse effect of welding process in material behaviour was discovered. Despite the concentrated heat of microplasma arc welding, post-weld heat treatment of the weld area is recommended to improve the mechanical behaviour of the welded joints.

scholarly journals Optimization of Metal Inert Gas Welding Process during Joining of Structural Steels- An Overview

2020 ◽  
Vol 184 ◽  
pp. 01028
Author(s):  
Ravindra Kumar Misra ◽  
Rajesh Kumar Porwal
Keyword(s):  
Heat Treatment ◽  
Welded Joints ◽  
Experimental Studies ◽  
Welding Process ◽  
Inert Gas ◽  
Fatigue Properties ◽  
Input Parameters ◽  
Metal Inert Gas Welding ◽  
Weld Heat

Metal Inert Gas welding is a fast, reliable and cost effective technique for joining of different ferrous materials and steels used in the construction of large structures like Fe410WA, IS2062, SS304, AISI1040 and AISI316 etc. To obtain better quality and performance of the steel welded joints, parameter optimisation of metal inert gas welding procedure and weld heat treatment process is carried out. In optimization work and studies, variables of GMAW process like welding voltage and current, speed of welding, WFR (rate of wire feed), GFR (rate of gas flow), type of gas used and effect of heat treatments are kept changing to get best combinations of input parameters for best quality of welded parts. The quality of welds is evaluated in terms of mechanical properties of welded joints like ultimate tensile and yield strength, elongation, microstructure, heat affected zone and defect free weld joints etc. Model and experimental studies are done in different combinations to get best combination of input parameters for steels. Studies by authors have identified the significance of input parameters in ascending order and some of them also quantified the optimal values of the input parameters. Pre and post weld heat treatment of structures is beneficial in improvement of mechanical and fatigue properties.

Assessment of the Fatigue Behaviour of Friction Stir Welded Joints: Aluminium Alloy 6082-T6

2007 ◽  
Vol 348-349 ◽  
pp. 209-212 ◽  
Author(s):  
Pedro Miguel Guimarães Pires Moreira ◽  
A.M.P. de Jesus ◽  
A.S. Ribeiro ◽  
Paulo Manuel Salgado Tavares de Castro
Keyword(s):  
Aluminium Alloy ◽  
Welded Joints ◽  
Base Material ◽  
Welding Process ◽  
Growth Curves ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Friction Stir ◽  
Crack Propagation Resistance ◽  
Strength And Ductility

A study on the fatigue behaviour of friction stir butt welds of 3mm thick 6082-T6 aluminium alloy was carried out. Monotonic tensile and cyclic tests of welded joints and base material were performed to understand the influence of the welding process on the static and fatigue properties. Microhardness profiles were measured and fatigue crack growth curves were determined for cracks growing in different locations of the weldments. Friction stir material exhibited lower strength and ductility properties than the base material. However, an enhanced crack propagation resistance is observed.

Fatigue Behaviour of Friction Stir Welded Steel Joints

2014 ◽  
Vol 891-892 ◽  
pp. 1488-1493 ◽  
Author(s):  
José Azevedo ◽  
Virgínia Infante ◽  
Luisa Quintino ◽  
Jorge dos Santos
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Steel Structures ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Welded Steel ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Steel Joints

The development and application of friction stir welding (FSW) technology in steel structures in the shipbuilding industry provide an effective tool of achieving superior joint integrity especially where reliability and damage tolerance are of major concerns. Since the shipbuilding components are inevitably subjected to dynamic or cyclic stresses in services, the fatigue properties of the friction stir welded joints must be properly evaluated to ensure the safety and longevity. This research intends to fulfill a clear knowledge gap that exists nowadays and, as such, it is dedicated to the study of welded steel shipbuilding joints in GL-A36 steel, with 4 mm thick. The fatigue resistance of base material and four plates in as-welded condition (using several different parameters, tools and pre-welding conditions) were investigated. The joints culminate globally with defect-free welds, from which tensile, microhardness, and fatigue analyses were performed. The fatigue tests were carried out with a constant amplitude loading, a stress ratio of R=0.1 and frequency between 100 and 120 Hz. The experimental results show the quality of the welding process applied to steel GL-A36 which is reflected in the mechanical properties of joints tested.

scholarly journals Contributions Regarding the Use of Mechanical Vibrations in Order to Improve the Properties of Steels and Welded Joints Used in Metal Constructions

2020 ◽  
Vol 21 (2) ◽  
pp. 67-71
Author(s):  
Gheorghe Novac ◽  
Bogdan Novac
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Significant Contribution ◽  
Welding Process ◽  
Internal Stresses ◽  
Welding Equipment ◽  
Welding Technology ◽  
Submerged Arc ◽  
Very High

The paper presents aspects regarding the influence of vibrations on the mechanical properties of welded joints, made with basic materials of Spanish and Romanian origin. In this research is presented the practical way to make the necessary assemblies for the proposed tests. The tests show that vibrations have a significant contribution to the quality of welded joints. This is explained by the appearance of several crystallization centres which makes the structure finer. By using vibrations, the atoms are rearranged in the structure, ensuring a proper de-tensioning. The stresses induced in welded metals are significantly reduced by the use of vibration during welding process. The addition materials have a significant contribution to the emergence of stresses in welded joints as well. These stresses can contribute to the appearance of microstructural constituents with significant hardness. The welding equipment and technologies used also have a significant contribution to the emergence of the remaining stresses. For example, the submerged arc welding technology (SAF) can introduce very high internal stresses. By using vibrations during the welding process, it is achieved a fine structure and a significant reduction of remaining stresses in the welded joints.

Development of Technology for Welding Repair of Steel Housings Using a Combination of Ultrasonic Vibrations and Forced Cooling

2020 ◽  
Vol 989 ◽  
pp. 747-752
Author(s):  
Marat R. Fatkullin ◽  
Ayrat M. Fayrushin ◽  
Rif G. Rizvanov
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Pool ◽  
Welded Joints ◽  
Arc Welding ◽  
Oil And Gas ◽  
Welding Process ◽  
Subsequent Heat Treatment ◽  
Manual Arc Welding ◽  
Forced Cooling

Now, one of the most pressing issues in the development of petroleum engineering is increasing the efficiency of apparatus and machines, as well as reducing material, energy and labor resources. During operation, oil-refining equipment over time destroyed by welded joints due to the impact of power and temperature loads, corrosion, and other factors. The cause of damage in welded joints of oil and gas equipment can be justified by the occurrence in them of structural heterogeneity and residual stresses during and after welding. Today manual arc welding is almost the only applicable in the repair of equipment for oil and gas processing, which require welding operations. The high temperature source of energy and the difference in deformation properties of parts are the cause of the occurrence of substantial residual stresses, which cause a change in shape, a significant decrease in strength, a decrease in the corrosion resistance of the metal, which adversely affects the durability and reliability of the structure. At present, the technology of repair with due to manual arc welding with the concomitant heating of the defective area and subsequent heat treatment is used. A complex of simultaneously proceeding processes accompanies the welding process: thermal effects on the metal in the heat-affected zone, metallurgical processes in the weld pool and crystallization of the metal in the weld pool. The repair technology presented by us, which consists in a combination of ultrasonic shock vibrations and forced cooling during the welding process, allows to improve the mechanical properties of the welded joint, as well as to refuse to carry out heating during welding and subsequent heat treatment.

scholarly journals Determination of Strain and Stress Fields in Welded Joints of S960-QC Steel

2017 ◽  
Vol 62 (4) ◽  
pp. 2081-2087 ◽  
Author(s):  
T. Pała ◽  
I. Dzioba
Keyword(s):  
Welded Joints ◽  
Experimental Studies ◽  
Welding Process ◽  
Tensile Tests ◽  
Stress Fields ◽  
Uniaxial Tensile ◽  
Displacement Fields ◽  
The Individual ◽  
Computational Part

Abstract The paper presents the results of two butt welded joints by conventional method. The welding process was performed using a variety of linear welding energy. The studies included experimental and computational part. In experimental studies determined the distribution of hardness and mechanical properties of the individual analyzed sections of welded joints. The data obtained were intended to determine the extent of zones in the welded joints that have certain strength characteristics. Also conducted uniaxial tensile tests of welded joints with the registration of displacement fields on the surface of specimens by means of Aramis video-system what the final result are images of strain fields map on the surface of welded joints. The resulting strain values were compared with the results of numerical computations FEM.

Numerical Simulation of Welding Thin Titanium Sheets

2013 ◽  
Vol 549 ◽  
pp. 407-414 ◽  
Author(s):  
Piotr Lacki ◽  
Konrad Adamus
Keyword(s):  
Electron Beam ◽  
Electron Beam Welding ◽  
Pure Titanium ◽  
Welding Process ◽  
Source Model ◽  
Commercially Pure Titanium ◽  
Structural Elements ◽  
Grade 5 ◽  
Titanium Grade ◽  
Sheet Deformation

Different titanium grades are used in aircraft construction because of titaniums unique properties. These materials are mostly joined by different welding methods. Electron beam welding technology is often used in the aircraft industry to join structural elements made of titanium alloys. The goal of the work is a numerical analysis of the electron beam welding process applied to joining thin titanium sheets. The analysis was performed using finite element method, FEM. Temperature distribution, size of heat affected zone (HAZ), depth and width of fusion zone were determined for the assumed heat source model. Thermo-mechanical (TMC) simulation of the electron beam welding process using FEM is presented in the paper. The joining of two sheets, one made of commercially pure titanium Grade 2 and the other made of titanium alloy Grade 5 (Ti6Al4V), is analysed in the work. For the sheet welding process distributions of temperature, effective stress, and sheet deformation were calculated.

scholarly journals Shielded Metal Arc and Thermite Welding Effect to Residual Stress, Hardness and Crack of R54-Rail Weld Joint

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Yurianto ◽  
Gunawan Dwi Haryadi ◽  
Sri Nugroho ◽  
Sulardjaka ◽  
Susilo Adi Widayanto
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Welding Process ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Crack Susceptibility

The heating and cooling at the end of the welding process can cause residual stresses that are permanent and remain in the welded joint. This study aims to evaluate the magnitude and direction of residual stresses on the base metal and heat-affected zone of rail joints welded by the manual shielded metal arc and thermite welding. This research supports the feasibility of welding for rail. The material used in this study is the R-54 rail type, and the procedure used two rail samples of one meter long each, welded using manual shielded metal arc welding and thermite welding. The base metal and heat-affected zone of the welded joints were scanned with neutron ray diffraction. The scan produces a spectrum pattern and reveals the direction of the residual stress along with it. We found the strain value contained in both types of welded joints by looking at the microstrain values, which we obtained using the Bragg equation. The results show that the magnitude and direction of the residual stress produced by manual shielded metal arc welding and thermite welding are not the same. Thermite welding produces lower residual stress (lower crack susceptibility) than manual shielded metal arc welding. The melt's freezing starts from the edge to the center of the weld to create random residual stresses. The residual stress results of both the manual shielded metal arc welding and thermite welding are still below the yield strength of the base metal.

Testing of Welded Joints between Pipes for Pressure Vessels Made of Hot Rolled Fine-Grained Steel P460NL1

2020 ◽  
Vol 1157 ◽  
pp. 15-20
Author(s):  
Miodrag Arsić ◽  
Srđan Bošnjak ◽  
Vencislav Grabulov ◽  
Mladen Mladenović ◽  
Zoran Savić
Keyword(s):  
Tensile Properties ◽  
Welded Joints ◽  
Arc Welding ◽  
Welded Joint ◽  
Welding Process ◽  
Pressure Vessels ◽  
Parent Material ◽  
Fine Grained ◽  
Hot Rolled ◽  
Material Standard

This paper contains results of tests performed in order to determine mechanical properties of steel P460NL1, used as filler material during the execution of welded joints. Arc welding of samples from which the specimens were taken was carried out through the application of welding process 111, because it is one of the processes for the execution of pipelines for pressure equipment. Microspecimens with diameter of Ø1,5 mm were tested in order to determine tensile properties of material taken from the heat-affected zone and weld metal, while specimens with diameter of Ø6 mm were tested in order to determine tensile properties of parent material. Standard Charpy V-notch specimens were used in order to determine impact energy. Results of metallographic tests which refer to the structure of a pipe welded joint are also presented.

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