scholarly journals Effect of Various Parameters on the Bead Geometry and Flexural Strength of MIG Welded Joint

Metal inert gas welding is the process in which a continuous coil of consumable electrode is used with inert gas shielding. It was extensively being used for Aluminum and Mg Alloys. But due to other alternatives available for, the cost of inter gas prohibited the use of MIG welding of steels. After the introduction of carbondioxide as shielding gas the economical viability in welding of steels was realized. The quality of weld joing and its productivity is influenced by the parameters such as arc current, wire feed rate, voltage, welding speed, torch angle, , nozzle to plate distance, welding position and gas flow direction. In the present work effect of gas flow rate, voltage and current are studied using Taguchi L-9 orthogonal array. The flexural strength, tensile strenght and bead geometry for various trails are computed and the optimum combination is obtained.

1993 ◽  
Vol 8 (3) ◽  
pp. 551-557 ◽  
Author(s):  
Bradley D. Heilman ◽  
Matthew A. Marston ◽  
Peter Y. Wong ◽  
Ioannis N. Miaoulis

Zone-melting recrystallization (ZMR) with a graphite strip heater is used to improve the material quality of thin film structures for microelectronic applications. The process takes place in a sealed chamber filled with an inert gas such as argon or helium. The effect of natural convection and conduction at the interface between the gas and film structure was studied both numerically and experimentally. Numerical simulations of the temperature profile in the film structure, and the flow pattern and temperature field in the gas were developed. Experimental observations in a scaled setup using a liquid medium verified the flow patterns calculated from the numerical model of the gas flow in the chamber. Results indicated that the gas is stagnant in the region below the strip heater; consequently, conduction from the strip heater to the wafer is prevalent. Outside the stagnant region, natural convection cools the film structure. These two effects combine to create a steeper thermal gradient across the entire wafer which can increase the thermal stresses in the film. The magnitude of this thermal gradient depends strongly on the thermal diffusivity of the gas. The configuration of the strip heater may significantly affect the amount of heat conduction in the stagnant region.


2020 ◽  
Vol 5 (2) ◽  
pp. 140-144
Author(s):  
Wenny Marthiana ◽  
Yovial Mahyoedin ◽  
Duskiardi Duskiardi ◽  
Afri Rahim

AbstrakPada proses produksi, pengaturan parameter poses memegang peranan penting terhadap tercapainya mutu produk yang dihasilkan. Pada proses pengelasan, salah satu parameter proses pengelasan yang harus diperhatikan adalah besar arus pengelasan. Kajian ini dilakukan untuk mengetahui besar kuat arus yang sesuai pada proses pengelasan material ST 37 menggunakan proses pengelasan MIG (Metal Inert Gas).  Pengujian dilakukan dengan memvariasikan besar kuat arus pengelasan yaitu pada 90A, 100A, 110A serta 120A. Pengujian tarik dilakukan terhadap hasil pengelasan tersebut. Hasil pengujian tarik menunjukkan, pengelasan menggunakan kuat arus sebesar 110A memberikan nilai yang maksimum pada beberapa besaran pengujian.  Untuk nilai tegangan tarik, σ memiliki nilai 16.9 kg/mm2, modulus elastisitas, E, 3.14 kg/mm2 serta Regangan ε, 5.42%. Kata kunci: pengelasan, Metal Inert Gas, Tegangan Tarik, modulus elastisitas  AbstractThe appropriate production parameter process plays an important role in fulfill the quality of the products such as mechanical properties like tensile strength and percentage of elongation of MIG welded joints.  Likewise, in the welding process, one of the welding process parameters that is welding current must be considered, since the welding current is most influential parameters affecting weld penetration, deposition rate, weld bead geometry and quality of weld metal. Variation of welding current on MIG (Metal Inert Gas) welding process on ST 37 specimen   was to examine the effects on like tensile strength and percentage of elongation and elasticity modulus.  From the experiment, it is found that when welding current increased up to 110 Ampere the tensile strength tends to incline then slightly decline when welding current increased, modulus elasticity value and percentage of elongation value as well.  The maximum value of tensile strength 16.9 kg/mm2 percentage of elongation value 5.42%. and modulus of elasticity 3.14 kg/mm2 were gained at 110 ampere welding current Keywords: welding process, Metal Inert Gas, Tensile strength, elasticity modulus ,percentage of elongation


Author(s):  
Bo Wang ◽  
Xunming Zhu ◽  
Hongchang Zhang ◽  
Hongtao Zhang ◽  
Jicai Feng

In this article, a novel hybrid welding process called plasma-TIG coupled arc welding was proposed to improve the efficiency and quality of welding by utilizing the full advantage of plasma and TIG welding processes. The two arcs of plasma and TIG were pulled into each other into one coupled arc under the effect of Lorentz force and plasma flow force during welding experiments. The arc behavior of coupled arc was studied by means of it’s arc profile, arc pressure and arc force conditions. The coupled arc pressure distribution measurements were performed. The effects of welding conditions on coupled arc pressure were evaluated and the maximum coupled arc pressure was improved compared with single-plasma arc and single-TIG arc. It was found that the maximum arc pressure was mainly determined by plasma arc current and plasma gas flow. According to the results, the proposed coupled arc welding process have both advantages of plasma arc and TIG method, and it has a broad application prospect.


Author(s):  
C. S. Iorio ◽  
O. A. Kabov

When a layer of volatile liquid is subject to a flow of inert gas, a non-uniform distribution of the evaporation rate is generated all along the interface. Being evaporation stronger at the inlet boundary of the layer, because of the maximal efficiency of the inert gas flow in removing vapor from the interface, a thermal gradient along the interface is generated. Two opposite mechanisms regulate the movement of the interface: the shear stress of the gas that entrains the interface in the direction of the flow and the thermo-capillary stress that forces the interface to move against the flow direction. Moreover, because of the overall cooling of the interface due to the evaporative process, a gradient normal to the interface is also created. It results in a potentially unstable situation that is strongly influenced by the flow rate of inert gas, the layer thickness and the liquid thermo-physical properties. The goal of the present work is to study numerically if and how the dynamic evolution of the liquid layer is driven by the above-mentioned mechanisms. The main results concern the evaluation of the influence of the thermal instability patterns, eventually generated by the concurrent action of non-uniform evaporation and thermo-capillary motion, on the heat transfer at the bottom liquid. The distribution of temperature and velocity in the gas and liquid bulk phase for different mass flow rate of inert gas has also been of interest.


2014 ◽  
Vol 941-944 ◽  
pp. 776-779 ◽  
Author(s):  
Kumar Molugaram ◽  
Jaya S. Shanker ◽  
Adepu Ramesh

Aggregate characteristics of shape, texture and grading influence on workability, finishability, bleeding, pumpability and segregation of fresh concrete and affects the strength, shrinkage, density, and durability of hardened concrete. About 80% of total volume of concrete consists of aggregate. Construction and durability problems have been reported due to poor mixture proportioning and variation on grading. Aggregate characteristics significantly affect the performance of Quality Concrete (QC) both in fresh and hardened state and have an impact on the cost effectiveness. Flaky and elongated particles lead to higher voids than cubical, rounded and well graded particles. The shape factor of aggregate plays a vital role in the design and performance of QC mix and it is mainly depends on the rock formation and type of crusher being used for crushing the aggregates. Flaky and elongated particles have larger specific surface area which results in higher demand of cement paste in cement concrete mix. These particles impede compaction or break during rolling and decrease the strength of the concrete structures. An attempt is made to study the effect of shape of aggregate on quality of the concrete used for the buildings and pavements. Initially an aggregate samples were collected from the stone crusher (two types) and prepared with different proportions of Flakiness and Elongation indices to conduct tests on properties of aggregates and compressive strength and flexural strength tests on concrete. The effect of different percentages from 0 to 50% of combined Flaky and Elongation Aggregates (CFEA) for quality concrete on the compressive and flexural strength of cement concrete is studied. The other properties of aggregate such as bulk density, impact value, water absorption have been studied for different shapes of aggregates. The cost analysis has been carried out with an optimum value of 30% CFEA in 1:3 proportions of flaky and elongated particles.


Author(s):  
Nikolay Ivanov ◽  
Vladimir V. Ris ◽  
Nikolay A. Tschur ◽  
Marina Zasimova
Keyword(s):  
Gas Flow ◽  

Author(s):  
Nur Maimun ◽  
Jihan Natassa ◽  
Wen Via Trisna ◽  
Yeye Supriatin

The accuracy in administering the diagnosis code was the important matter for medical recorder, quality of data was the most important thing for health information management of medical recorder. This study aims to know the coder competency for accuracy and precision of using ICD 10 at X Hospital in Pekanbaru. This study was a qualitative method with case study implementation from five informan. The result show that medical personnel (doctor) have never received a training about coding, doctors writing that hard and difficult to read, failure for making diagnoses code or procedures, doctor used an usual abbreviations that are not standard, theres still an officer who are not understand about the nomenclature and mastering anatomy phatology, facilities and infrastructure were supported for accuracy and precision of the existing code. The errors of coding always happen because there is a human error. The accuracy and precision in coding very influence against the cost of INA CBGs, medical and the committee did most of the work in the case of severity level III, while medical record had a role in monitoring or evaluation of coding implementation. If there are resumes that is not clearly case mix team check file needed medical record the result the diagnoses or coding for conformity. Keywords: coder competency, accuracy and precision of coding, ICD 10


2017 ◽  
pp. 139-145
Author(s):  
R. I. Hamidullin ◽  
L. B. Senkevich

A study of the quality of the development of estimate documentation on the cost of construction at all stages of the implementation of large projects in the oil and gas industry is conducted. The main problems that arise in construction organizations are indicated. The analysis of the choice of the perfect methodology of mathematical modeling of the investigated business process for improving the activity of budget calculations, conducting quality assessment of estimates and criteria for automation of design estimates is performed.


2015 ◽  
Vol 6 (1) ◽  
pp. 50-57
Author(s):  
Rizqa Raaiqa Bintana ◽  
Putri Aisyiyah Rakhma Devi ◽  
Umi Laili Yuhana

The quality of the software can be measured by its return on investment. Factors which may affect the return on investment (ROI) is the tangible factors (such as the cost) dan intangible factors (such as the impact of software to the users or stakeholder). The factor of the software itself are assessed through reviewing, testing, process audit, and performance of software. This paper discusses the consideration of return on investment (ROI) assessment criteria derived from the software and its users. These criteria indicate that the approach may support a rational consideration of all relevant criteria when evaluating software, and shows examples of actual return on investment models. Conducted an analysis of the assessment criteria that affect the return on investment if these criteria have a disproportionate effort that resulted in a return on investment of a software decreased. Index Terms - Assessment criteria, Quality assurance, Return on Investment, Software product


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