scholarly journals Effect of Single Oxide Fluxes on Morphology and Mechanical Properties of ATIG on 316 L Austenitic Stainless Steel Welds

2018 ◽  
Vol 8 (3) ◽  
pp. 3064-3072 ◽  
Author(s):  
A. Hdhibi ◽  
K. Touileb ◽  
R. Djoudjou ◽  
A. Ouis ◽  
M. L. Bouazizi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Photoelectron Spectroscopy ◽  
Welding Current ◽  
Inert Gas ◽  
Level Energy ◽  
Bead Geometry ◽  
Weld Bead Geometry ◽  
The Impact

Tungsten inert gas (TIG) is a wide common process used in fabrication due to its low cost equipment, high quality and accuracy welds but has low productivity related to the low penetration depth in single pass. A new perspective, the Activated Tungsten Inert Gas (ATIG), in which the same equipment as TIG is used, except that a thin layer of activated flux is deposited on a workpiece surface. In this work, eight kinds of oxides were tested on 316L austenitic stainless steel. Three levels of welding current were used to study the effect of different activating fluxes on weld bead geometry and mechanical properties. X-ray Photoelectron Spectroscopy (XPS) was used for the first and the second level energy for different ATIG welds to analyze the relationship between the weld shape and oxygen content in welds. The experimental results showed that the weld profile is related to the thermodynamic stability of selected oxides and in relation to the energy provided. ATIG with TiO2, SiO2, MnO2 oxides presented the deepest welds followed by Cr2O3, Fe2O3, and ZnO. Finally ZrO2, CaO oxides had no effect on the weld depth. The ATIG welded joint showed better tensile strength than TIG. The ATIG hardness measurements carried out showed also better if not the same as TIG weld except for the Silicon oxide weld. Results of the impact test showed that, except for the titanium dioxide TiO2 which has a good benefit, the weldment using the other oxide fluxes exhibits worse withstanding to sudden shock than TIG welding.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

Development of Mathematical Models for Prediction of Weld Bead Geometry of GTAW Stainless Steel

2017 ◽  
Vol 867 ◽  
pp. 88-96
Author(s):  
S.M. Ravikumar ◽  
P. Vijian
Keyword(s):  
Stainless Steel ◽  
Process Parameters ◽  
Welding Current ◽  
Weld Bead ◽  
304 Stainless Steel ◽  
Graphical Form ◽  
Bead Geometry ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width

Welding input process parameters are playing a very significant role in determining the weld bead quality. The quality of the joint can be defined in terms of properties such as weld bead geometry, mechanical properties and distortion. Experiments were conducted to develop models, using a three factor, five level factorial design for 304 stainless steel as base plate with ER 308L filler wire of 1.6 mm diameter. The purpose of this study is to develop the mathematical model and compare the observed output values with predicted output values. Welding current, welding speed and nozzle to plate distance were chosen as input parameters, while depth of penetration, weld bead width, reinforcement and dilution as output parameters. The models developed have been checked for their adequacy. Confirmation experiments were also conducted and the results show that the models developed can predict the bead geometries and dilution with reasonable accuracy. The direct and interaction effect of the process parameters on bead geometry are presented in graphical form.

scholarly journals Analisa Pengaruh Variasi Arus Listrik Pengelasan Terhadap Kekuatan Sambungan Pengelasan MIG Pada Material ST 37

2020 ◽  
Vol 5 (2) ◽  
pp. 140-144
Author(s):  
Wenny Marthiana ◽  
Yovial Mahyoedin ◽  
Duskiardi Duskiardi ◽  
Afri Rahim
Keyword(s):  
Tensile Strength ◽  
Elasticity Modulus ◽  
Welding Process ◽  
Welding Current ◽  
Inert Gas ◽  
Bead Geometry ◽  
Weld Bead Geometry ◽  
Metal Inert Gas Welding ◽  
Influential Parameters

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

Application of Artificial Neural Networks to Estimate Tensile Strength of Austenitic Stainless Steel During Metal Inert Gas Welding Process

2021 ◽  
pp. 197-221
Author(s):  
Sudipto Chaki ◽  
Dipankar Bose
Keyword(s):  
Neural Networks ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Artificial Neural Networks ◽  
Austenitic Stainless Steel ◽  
Welding Current ◽  
Inert Gas ◽  
Mig Welding ◽  
Artificial Neural ◽  
Full Factorial Experimental Design

In the present work, artificial neural networks (ANN) have been used to model the complex relationship between input-output parameters of metal inert gas (MIG) welding processes. Four ANN training algorithms such as back propagation neural network (BPNN) with gradient descent momentum (GDM), BPNN with Levenberg Marquardt (LM) algorithm, BPNN with Bayesian regularization (BR), and radial basis function networks (RBFN) method have been used for prediction modelling. An experimentation based on full factorial experimental design has been conducted on MIG welding of austenitic stainless steel of grade-304 where welding current, welding speed, and voltage have been considered as input parameters, and tensile strength has been considered as measurable output parameter. The dataset so constituted is used for ANN modelling. Altogether, 40 different ANN architectures have been trained and tested using the above-mentioned algorithms, and 3-11-1 ANN architecture trained using BPNN with BR has been considered to show best prediction capability with mean % absolute error of 0.354%.

Performance of weld bead profile during A-TIG welding on nitrogen alloyed stainless steel

2021 ◽  
Author(s):  
Akash Deep ◽  
Vivek Singh ◽  
Som Ashutosh ◽  
M. Chandrasekaran ◽  
Dixit Patel
Keyword(s):  
Stainless Steel ◽  
Welding Process ◽  
Weld Bead ◽  
Tig Welding ◽  
Inert Gas ◽  
Bead Geometry ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
A Tig Welding ◽  
Arc Welding Process

Abstract Austenitic stainless steel (ASS) is widely fabricated by tungsten inert gas (TIG) welding for aesthetic look and superior mechanical properties while compared to other arc welding process. Hitherto, the limitation of this process is low depth of penetration and less productivity. To overcome this problem activated tungsten inert gas (A-TIG) welding process is employed as an alternative. In this investigation the welding performance of conventional TIG welding is compared with A-TIG process using TiO2 and SiO2 flux with respect to weld bead geometry. The experimental investigation on A-TIG welding of ASS-201 grade shows TiO2 flux helps in achieve higher penetration as compared to SiO2 flux. While welding with SiO2 the hardness in HAZ and weld region higher than that of TIG welding process.

scholarly journals Mechanical Properties and Microstructure of TIG and ATIG Welded 316L Austenitic Stainless Steel with Multi-Components Flux Optimization Using Mixing Design Method and Particle Swarm Optimization (PSO)

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7139
Author(s):  
Abdeljlil Chihaoui Hedhibi ◽  
Kamel Touileb ◽  
Rachid Djoudjou ◽  
Abousoufiane Ouis ◽  
Hussein Alrobei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Particle Swarm Optimization ◽  
Design Method ◽  
Weld Zone ◽  
Particle Swarm ◽  
Inert Gas ◽  
Swarm Optimization ◽  
316L Austenitic Stainless Steel ◽  
The Impact

In this study, the effects of pseudo-ternary oxides on mechanical properties and microstructure of 316L stainless steel tungsten inert gas (TIG) and activating tungsten inert gas (ATIG) welded joints were investigated. The novelty in this work is introducing a metaheuristic technique called the particle swarm optimization (PSO) method to develop a mathematical model of the ultimate tensile strength (UTS) in terms of proportions of oxides flux. A constrained optimization algorithm available in Matlab 2020 optimization toolbox is used to find the optimal percentages of the selected powders that provide the maximum UTS. The study indicates that the optimal composition of flux was: 32% Cr2O3, 43% ZrO2, 8% Si2O, and 17% CaF2. The UTS was 571 MPa for conventional TIG weld and rose to 600 MPa for the optimal ATIG flux. The obtained result of hardness for the optimal ATIG was 176 HV against 175 HV for conventional TIG weld. The energy absorbed in the weld zone during the impact test was 267 J/cm2 for the optimal ATIG weld and slightly higher than that of conventional TIG weld 256 J/cm2. Fracture surface examined by scanning electron microscope (SEM) shows ductile fracture for ATIG weld with small and multiple dimples in comparison for TIG weld. Moreover, the depth of optimized flux is greater than that of TIG weld by two times. The ratio D/W was improved by 3.13 times. Energy dispersive spectroscopy (EDS) analysis shows traces of the sulfur element in the TIG weld zone.

Study of solidification behaviour and mechanical properties of arc stud welded AISI 316L stainless steel

2019 ◽  
Vol 1 (97) ◽  
pp. 5-14 ◽  
Author(s):  
M.H. Abass ◽  
M.S. Alali ◽  
W.S. Abbas ◽  
A.A. Shehab
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
316L Stainless Steel ◽  
Welding Current ◽  
Primary Phase ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel ◽  
Microstructure And Mechanical Properties ◽  
Steel Stud

Purpose: This paper aims to investigate the impact of arc stud welding (ASW) process parameters on the microstructure and mechanical properties of AISI 316L stainless steel stud/plate joint. Design/methodology/approach: The weld performed using ASW machine. The influence of welding current and time on solidification mode and microstructure of the fusion zone (FZ) was investigated using optical microscope and scanning electron microscope (SEM). Microhardness and torque strength tests were utilised to evaluate the mechanical properties of the welding joint. Findings: The results showed that different solidification modes and microstructure were developed in the FZ. At 400 and 600 A welding currents with 0.2 s welding time, FZ microstructure characterised with single phase austenite or austenite as a primary phase. While with 800 A and 0.2 s, the microstructure consisted of ferrite as a primary phase. Highest hardness and maximum torque strength were recorded with 800 A. Solidification cracking was detected in the FZ at fully austenitic microstructure region. Research limitations/implications: The main challenge in this work was how to avoid the arc blow phenomenon, which is necessary to generate above 300 A. The formation of arc blow can affect negatively on mechanical and metallurgical properties of the weld. Practical implications: ASW of austenitic stainless steel are used in multiple industrial sectors such as heat exchangers, boilers, furnace, exhaust of nuclear power plant. Thus, controlling of solidification modes plays an important role in enhancing weld properties. Originality/value: Study the influence of welding current and time of ASW process on solidification modes, microstructure and mechanical properties of AISI 316 austenitic stainless steel stud/plate joint.

Effect of Static Aging on Mechanical Properties of an 18Cr-8Ni-W-Nb-V-N Stainless Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2211-2216
Author(s):  
Ilya Nikulin ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Early Stage ◽  
Secondary Phase ◽  
Fracture Mechanisms ◽  
Aged Condition ◽  
The Impact

The interrelations between microstructure, precipitation and mechanical properties of the 18Cr-8Ni-W-Nb-V-N austenitic stainless steel were examined under long-term aging at 650°C. It was shown that aging leads to decreasing strength characteristics with increasing aging time despite the fact that hardness tends to increase. In none-aged condition the present steel exhibits superior impact toughness of about 255 J/cm-2. This values decreases gradually at the early stage of the aging. After 1000 hours exposure the impact toughness is 195 J/cm-2 and decreases sharply to 135 J/cm-2 at 3000 hours. However, an evidence for ductile fracture was found even after long-term aging. Degradation in impact toughness and mechanical properties with aging is discussed in relation to microstructure evolution, precipitations of the secondary phase and fracture mechanisms.

Parametric Optimization of TIG Welding on 316L Austenitic Stainless Steel by Grey-Based Taguchi Method

2011 ◽  
Vol 383-390 ◽  
pp. 4667-4671 ◽  
Author(s):  
Nanda Naik Korra ◽  
K.R. Balasubramanian
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Gas Flow ◽  
Welding Process ◽  
Weld Bead ◽  
Bead Geometry ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width ◽  
Input Parameters

Gas Tungsten Arc Welding (GTAW) is one of the most widely used welding process in industry. The input parameters play a very significant role in determining the quality of a welded joint (geometry of weld bead). The joint quality can be evaluated by studying the features of weld bead geometry (output parameters) such as Bead Width (BW), Bead Height (BH) and Depth of Penetration (DP). Present study focused on welding of austenitic stainless steel sheets using GTAW process with 316L material. The output variables are determined according to gas flow rate, travel speed and current. Grey relational analysis is applied to optimize the input parameters simultaneously considering the multiple output variables. Finally, confirmation experiment has been conducted to validate the optimized parameters and found to be correlated.

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