scholarly journals Determining the Degree of Admixing Rate of the Base Material and the Melting Efficiency in Single-Bead Surface Welds Using Different Methods, Including New Approaches

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1479
Author(s):  
Matija Zorc ◽  
Aleš Nagode ◽  
Borut Kosec ◽  
Borut Zorc
Keyword(s):  
Cross Sections ◽  
Base Material ◽  
Welding Process ◽  
Precise Determination ◽  
Welding Parameters ◽  
Negative Consequences ◽  
Surface Areas ◽  
Bead Surface ◽  
Single Bead ◽  
Surface Welding

The precise determination of the admixing rate of the base material for certain welding parameters is very important because of the possible negative consequences. As such, it is the basis for corrections in welding technology. In the article, experimental and theoretical determinations of the admixing rate in single-bead surface welds that were arc welded onto S355 steel with different alloyed-steel-coated electrodes are discussed. The admixing rate was experimentally estimated from the ratio of the surface areas of metallographic cross-sections, from the ratios of the height and from chemical analyses of different regions of the surface weld, while it was theoretically estimated from the characteristics of the welding process and material constants. One of the key characteristics of the welding process is the melting efficiency, which can be estimated by means of different equations and from knowledge of the heat balance of the welding process. Both the average melting efficiency of the surface welding on the medium-thick S355 steel plate and the average admixing rate of the S355 steel into the surface welds have the same value, i.e., approximately 30%. New equations for estimating the melting efficiency of the arc welding with a coated electrode were developed on the basis of the results.

scholarly journals Analysis of the Mixing of Filler and Base Materials in Arc-Welded Single-Bead Surface Welds Using an EDXS Method

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 217
Author(s):  
Borut Zorc ◽  
Matija Zorc ◽  
Aleš Nagode
Keyword(s):  
Chemical Composition ◽  
Cross Sections ◽  
Steel Plate ◽  
Influencing Factor ◽  
Base Material ◽  
Arithmetic Means ◽  
X Ray ◽  
Base Materials ◽  
Bead Surface ◽  
Single Bead

This article deals with an analysis of mixing and determines the admixing rate of a base S355 steel plate in single-bead surface welds by measuring the chemical composition using a plane-scan energy dispersive X-ray spectroscopy (EDXS) on metallographic cross-sections. The results show that obtaining a larger number of EDXS measurements does not necessarily lead to obtaining a more accurate admixing rate. Due to the ever-present segregations that are generally near the base material, the disadvantage of this method is the subjective influence of the SEM operator on the estimated admixing rate. To obtain relevant results, a sufficiently wide area of well-mixed melt, including segregations, must be analyzed. This study showed that by using a sufficiently large number of appropriately selected sites with a sufficiently large surface area, it is possible to estimate the admixing rate from the chemical composition with an accuracy of ≥96% for the geometrically determined admixing rate D = 30%. From several equations, the best result showed an equation which is the arithmetic mean of the two different arithmetic means and in which the artificial influencing factor of the segregations of the base material is taken into account. With this equation, the same value of admixing rate, D = 30%, was obtained using the comparative geometric method.

Experimental Investigations on Aluminium Ultrasonic Welding Parameters

2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai
Keyword(s):  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Experimental Investigations ◽  
Welding Parameters ◽  
Material Structure ◽  
Welding Temperature ◽  
Wide Range ◽  
Made In

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.

Recommendations for Submerged Arc Spiral Welding With Optimized CTOD Properties

2018 ◽  
Author(s):  
Martin Liebeherr ◽  
Özlem E. Güngör ◽  
Nuria Sanchez ◽  
Hervé Luccioni ◽  
Nenad Ilic
Keyword(s):  
Weld Metal ◽  
Base Material ◽  
Welding Process ◽  
Experimental Program ◽  
Welding Parameters ◽  
Pipe Production ◽  
Filler Wire ◽  
Crack Tip Opening Displacement ◽  
Wide Range ◽  
Submerged Arc

Many pipe mills may not be familiar with a Crack Tip Opening Displacement (CTOD) requirement on the pipe seam weld, nor will they find easily relevant information in open literature. Influencing — and certainly not independent — factors are: welding parameters, base material and consumable selection. Out of these, the welding parameters such as heat input and cooling rate cannot be varied over a wide range during the pipe production, which means that the leverage is rather limited at the given welding process. The properties of the heat affected zone will be mainly affected by the base material, while the properties of the weld metal will be affected by both, base material and filler wire selection. In particular with respect to the weld metal properties it will be difficult to obtain general quantitative information. For example, a welding consumable supplier will readily provide the properties of the filler wires but would be unable to predict the changes caused by the dilution from any base material in the weld pool and specific welding procedures that may have been used. To support the pipe mills in the selection of the consumables for submerged arc welding, an experimental program was launched with the aim to provide recommendations on how to optimize CTOD toughness of the spiral weld seam. For this, a large number of welds were produced on 20 mm thick X70 coil samples, with eight different filler wire combinations, using a 2-wire (tandem) set-up for both the inside and outside weld. Welding parameters were kept constant. The welding program was applied to two different X70 steels to determine a potential influence of the micro-alloying elements, particularly Nb. The results show clearly that a careful consumable selection is required for obtaining acceptable CTOD toughness in the weld metal. Ni-Mo and Ti-B additions to the weld metal are found to be beneficial with both steel concepts. Mo addition alone both to the ID and OD welds was clearly not a suitable selection.

Mechanical Properties and Corrosion Resistance of Friction Stir Welded Dissimilar Aluminum Alloys 2219 to 5083

2015 ◽  
Vol 813-814 ◽  
pp. 203-207
Author(s):  
M. Koilraj ◽  
A. Sathesh Kumar ◽  
D.L. Belgin Paul ◽  
S.R. Koteswara Rao
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Weld Nugget ◽  
Welding Parameters ◽  
General Corrosion ◽  
Test Results ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
Shoulder Diameter ◽  
Mechanical Properties And Corrosion

In this paper, 6 mm thickness dissimilar aluminium alloys of 5083 (H321) and 2219 (O) butt joints were fabricated successfully by friction stir welding process. The quality joints were obtained for the welding parameters of 35 mm/min and 650 rpm with the shoulder diameter to pin diameter ratio as 3. Macrostructure study shows that the interface between the weld nugget and TMAZ is smooth and clear with a flow arm extending towards the top surface of the weld in the 2219 side. The boundary on the 5083 side between the weld nugget and the TMAZ was irregular. The obtained joint efficiency is around 92.57% based on the UTS of the softer material (AA2219). The tensile test results showed that the specimens failed in the heat affected zone of the softer base material 2219. The hardness values in the stirred zone are higher than the softer base material of alloy 2219. The friction stir welded dissimilar joint 2219-5083 exhibited better general corrosion characteristics than the 2219-2219 weld and 2219 base material.

scholarly journals Friction stir welding of new electronic packaging materials SiCp/Al composite with T-joint

2018 ◽  
Vol 38 (3) ◽  
pp. 352-359
Author(s):  
Zeng Gao ◽  
Jianguang Feng ◽  
Huanyu Yang ◽  
Jukka Pakkanen ◽  
Jitai Niu
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Welding Process ◽  
Experimental Results ◽  
Homogeneous Distribution ◽  
Welding Parameters ◽  
Matrix Composites ◽  
Friction Stir ◽  
Lower Temperature ◽  
Gas Tightness

Using friction stir welding, the electronic container box and lid made from aluminium matrix composites with reinforcement of SiC particle (15 vol% SiCp/Al-MMCs) was welded successfully with T-joint. The temperature distribution of box during the process, mechanical property and microstructure of the joint as well as gas tightness of welded box was investigated. The experimental results indicated that the satisfactory T-joint can be obtained under appropriate friction stir welding parameters. During the welding process, the bottom center, which was used to place the electronic component, reached a quite lower temperature of 100°C. That can ensure safety of components in the box. After the welding process, the microstructure in stir zone was better than in base material due to the refining and homogeneous distribution of the SiC particles. The experimental results showed that the electronic container box after friction stir welding had gas tightness. The He-leakage rate was under 10-8 Pa•m3/s.

Feasibility study of welding dissimilar Advanced and Ultra High Strength Steels

2020 ◽  
Vol 59 (1) ◽  
pp. 54-66
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Antti Salminen ◽  
Mvola Belinga ◽  
Xiaochen Yang
Keyword(s):  
Heat Input ◽  
High Strength Steel ◽  
Gas Metal Arc Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Hardness Test ◽  
Welding Parameter ◽  
Welding Parameters

AbstractThis study concerns the weldability of dissimilar Ultra high-strength steel (UHSS) and advanced high-strength steel (AHSS), which is used in the modern machine industry. The materials offered superior strength as well as relatively low weight, which reduces microstructure contamination during a live cycle. The choice of the welding process base of the base material (BM) and welding parameters is essential to improve the weld joint quality. S700MC/S960QC was welded using a gas metal arc welding (GMAW) process and overmatched filler wire, which was performed using three heat input (7, 10, and 15 kJ/cm). The weld samples were characterized by a Vickers-hardness test, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The test reveals a decrease of softening areas in the HAZ and the formation of the stable formation of Bainite-Ferrite for S700MC and Bainite-martensite for S960QC when the heat input of 10 kJ/cm is used. It is recommended to use the GMAW process and Laser welding (Laser beam-MIG), with an optimal welding parameter, which will be achieved a high quality of manufacturing products.

An investigation into the effect of welding parameters on fatigue crack growth rate and fracture toughness in friction stir welded copper sheets

2015 ◽  
Vol 232 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Ali Alavi Nia ◽  
Ali Shirazi
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Heat Affected Zone ◽  
Base Material ◽  
Welding Process ◽  
Stir Zone ◽  
Welding Parameters ◽  
Friction Stir

In the present study, the effect of various factors of friction stir welding including rotational and traverse speeds of tool and in fact, the amount of the heat transferred within welding was evaluated on the resistance to fatigue crack growth and fracture toughness in different zones of welding copper sheets. In order to better assess these two properties, other mechanical properties such as tensile strength and hardness were also studied and the microstructure of different zones of welds was investigated using optic and electron microscopies. By doing this study, it became clear that the less the heat transferred to the plunging during the welding process, the better properties the resulting welds will have which well justifies the use of cooling in this study. Transferring heat to plunging causes the growth of grains in various zones and can cause the fatigue crack growth in heat-affected zone to increase averagely about 4.2 times the base material for different Δ K. In contrast, the occurrence of dynamic recrystallization in the stir zone as well as fragmentizing and alignment of grains in this zone can increase the resistance to fatigue crack growth up to 9-fold the resistance of the base material. The other interesting result of this study was that although the properties of stir zone improve by increasing the number of welding passes, the properties of its weakest zone i.e. the heat-affected zone will decline.

Mechanical Behaviour of Al-Li Alloy Joints by Different Friction Stir Welding Parameters

2014 ◽  
Vol 1051 ◽  
pp. 799-807 ◽  
Author(s):  
Dan Dan Zhang ◽  
Wen Qing Qu ◽  
Qun Bo Lv ◽  
Yang Yang Liu ◽  
Wei Yan Li ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Base Material ◽  
Welding Process ◽  
Fatigue Properties ◽  
Welding Parameters ◽  
Fatigue Lifetime ◽  
Friction Stir ◽  
The Relationship ◽  
Microstructure And Mechanical Property ◽  
Made In

In this study, the Al-Li alloy plates were friction stir welded (FSW) at different welding parameters, and the effect of welding parameters on the hardness, tensile and fatigue properties of the butted and lapped FSWed joints were investigated. The experimental results showed that the ultimate strength and elongation of butted joints decreased as the heat input increasing, and the maximum ultimate strength of the joints was equivalent to 83% that of the base material. By comparison of the heat inputs during welding process at different parameter combinations, the relationship between the microstructure and mechanical property of FSWed joints was established. For the overlapped welds made in 2mm thick plates of Al-Li-S4 and 2099 alloys, the hooking defect was a typical and inevitable defect appearing on the TMAZ of both advancing and retreating sides, which would adversely damage the mechanical properties of overlapped joints. Furthermore, the length of pin significantly affected the tensile property of overlapped joints, when the length of pin varies from 2.8mm to 2.5mm, the ultimate strength increased 14% to 20%. In addition, the fatigue lifetime of overlapped joints was lower than that of butted joints and base metal.

Friction Stir Welding of Ti-6Al-4V Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 574-579 ◽  
Author(s):  
Paola Leo ◽  
Emanuela Cerri
Keyword(s):  
Friction Stir Welding ◽  
Cross Sections ◽  
Weight Ratio ◽  
Base Material ◽  
Welding Process ◽  
Lamellar Microstructure ◽  
Travel Speed ◽  
Boundary Phase ◽  
Welding Seam ◽  
Friction Stir

Titanium (Ti) and its alloys are used extensively in aerospace industry where there is a critical need for material with high strength-to–weight ratio and high elevate temperature properties. Friction stir welding (FSW) is a new solid state welding process in which a cylindrical–shouldered tool with an extended pin is rotated and gradually plunged into the joint between the workpieces to be welded. The material is frictionally heated to a temperature at which it becomes more plastic but no melting of the blanks to be welded is reached therefore the presence of defects typically observed in and close to the welding seam is strongly reduced. The final result is the improvement of the mechanical performances of the welded joints even in some materials with poor fusion weldability. In this paper the authors analyze the microstructure of FSW joints of Ti-6Al-4V processed at the same travel speed (50 mm/min) and at different rotation speed (300-500rpm). The microstructure of base material (BM) is not homogenous. It is characterized by distorted α/ β lamellar microstructure together with smashed zone of fragmented β layer and β retained grain boundary phase. The BM has been welded in the as received state, without any previous heat treatment. The microstructure of the transverse section of joints is not homogeneous. Close to the top of weld cross sections a much finer microstructure than the initial condition has been observed while in the center of the joints the microstructure is mixed and less refined.

Effect of Process Parameters on the Mechanical Properties of Friction Stir Welded Al-Li Alloy Butt Joints

2012 ◽  
Vol 155-156 ◽  
pp. 1096-1101
Author(s):  
D.D. Zhang ◽  
W.Q. Qu ◽  
Q. Meng ◽  
P. Chai ◽  
G.H. Luan ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Heat Input ◽  
Base Material ◽  
Welding Process ◽  
Weld Nugget ◽  
Tensile Fracture ◽  
Welding Parameters ◽  
Butt Joints ◽  
Obvious Effect ◽  
Friction Stir

Friction stir welding (FSW) is a new and promising welding process that can produce low-cost and high-quality joints of Al-Li alloy. In order to demonstrate the friction stir weldability of Al-Li alloy and determine optimum welding parameters, the effect of FSW welding parameters on the tensile properties of the Al-Li alloy butt joints has been studied in this paper. The results showed that, when the heat input increased, the ultimate strength and elongation of butt joints decreased. For the Al-Li alloy butt structure with the thickness of 2mm, the optimum parameters were the rotation speed of 600 rpm, the welding speed of 400mm/min, and the ultimate strength of butt structure was the maximum strength, arrived at 413MPa, equivalent to 83% that of the base material. Furthermore, it was found from the microstructural observation that, the welding parameters had obvious effect on the grain size of welded zone. As the heat input increasing, the grains of weld nugget and heat affected zone became larger accordingly. In addition, a special layered phenomenon appeared at tensile fracture surface, the tensile cracks initiated from the surface on welded zone near the thermomechanically affected zone(TMAZ) on the advancing side and then grew along the interface between the weld nugget and the TMAZ. The overall fracture mode was ductile - brittle hybrid fracture.

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