Hot corrosion performance of bare and pulsed current welded Fe-based A-286 alloy in chlorine and sulphur environment

2021 ◽  
pp. 095440892110434
Author(s):  
S M Muthu ◽  
R Dinek ◽  
P Mohan ◽  
K Jithesh ◽  
M Arivarasu
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Hot Corrosion ◽  
Research Work ◽  
Welding Process ◽  
Mapping Technique ◽  
Porous Iron ◽  
Pulsed Current ◽  
Bare Metal ◽  
Corrosion Performance

This present research work focuses on the hot corrosion performance of the base metal, weldment, and weld metal of A-286 alloy in sodium sulphate (Na2SO4)–5% sodium chloride (NaCl)–7.5% sodium metavanadate (NaVO3) (3SM) atmosphere at 700 °C. A pulsed current gas tungsten arc welding process is employed to make a similar joining of A-286 alloy using the filler material ERNiCrMo-3. The corrosion kinetics of the specimens has been determined using the thermo-gravimetric technique. The phase compositions of the reaction products are studied by X-ray diffraction, and the surface morphology of the scales is explored by scanning electron microscope analysis. The corroded samples are subjected to a cross-sectional study to ensure the corrosion attack and scales thickness using a SEM with elemental mapping technique. The result indicates that weldment showed better corrosion resistance than bare metal. A thick oxide scale could be found in the bare metal specimen than the weld metal. In the case of base metal, the formation of non-adherent and porous iron (III) oxide (Fe2O3) leads to rapid corrosion. The weight gain of weldment is about 1.96 and 1.13 times less than bare alloy and weld metal.

Combining CaO–SiO2–TiO2 and CaO–SiO2–Al2O3 ternary phase systems for design of bimetallic welds

2021 ◽  
Vol 235 (8) ◽  
pp. 1271-1283
Author(s):  
Deepak Bhandari ◽  
Rahul Chhibber ◽  
Lochan Sharma ◽  
Navneet Arora ◽  
Rajeev Mehta
Keyword(s):  
Weld Metal ◽  
Power Plants ◽  
Ternary Phase ◽  
Desirability Function ◽  
Manganese Content ◽  
Research Work ◽  
Welding Process ◽  
Delta Ferrite ◽  
Electrode Coating ◽  
Phase Systems

The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants. The occurrences of welding defects generally depend on the filler electrode as well as the electrode coatings during shielded metal arc welding process. This study involves the design of austenitic stainless steel welding electrodes for SS304L–SA516 bimetallic welds. The objective of research work includes the novel design of Al2O3–TiO2–CaO–SiO2 coatings by combining two ternary phase systems using extreme vertices mixture design methodology to analyze the effect of key coating constituents on the weld metal chemistry and mechanical properties of the welds. The significant effect of electrode coating constituent CaO on weld metal manganese content is observed which further improves the toughness of bimetallic weld joints. Various regression models have been developed for the weld responses and multi objective optimisation approach using composite desirability function has been adopted for identifying the optimized set of electrode coating compositions. The role of delta ferrite content in promoting the favourable solidification mode has been studied through microstructural examination.

scholarly journals A Combination of Keyhole GTAW with a Trapezoidal Interlayer: A New Insight into Armour Steel Welding

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3571 ◽  
Author(s):  
Zhenyu Fei ◽  
Zengxi Pan ◽  
Dominic Cuiuri ◽  
Huijun Li ◽  
Azdiar A. Gazder
Keyword(s):  
Chemical Composition ◽  
Weld Metal ◽  
Base Metal ◽  
Welding Process ◽  
Charpy Impact ◽  
Filler Materials ◽  
Temperature Phase ◽  
Ballistic Performance ◽  
Two Phase ◽  
Armour Steel

The ballistic performance of armour steel welds using austenitic filler materials is poor on account of the disparity in the mechanical properties of the weld and base metals. Consequently, a novel Keyhole Gas Tungsten Arc Welding process with a trapezoidal AISI309 austenitic stainless steel interlayer was developed to tailor chemical composition and microstructure by controlling the solidification sequence. Results show that the dilution rate in the weld metal region can reach up to 43.5% by placing a specially designed interlayer in between the base metal, providing a major scope for microstructure modification. Detailed weld analysis was undertaken by X-ray diffraction, optical and secondary and transmission electron microscopy, energy dispersive spectroscopy and electron back-scattering diffraction. The results from Vickers hardness indents and Charpy impact toughness testing at −40 °C show that the properties of the weld metal region are comparable to that of the base metal. This is ascribed to the weld metal comprising a two phase microstructure of martensite and retained austenite, which contribute to improvements in strength and toughness, respectively. Furthermore, the tailored chemical composition, microstructure and low temperature phase transformation in the weld metal may reduce the tendency toward both solidification cracking and hydrogen assisted cold cracking.

Application of FIB/SEM/EBSD for Evaluation of Residual Strains and Their Relationship to Weld Metal Hydrogen Assisted Cold Cracking

2012 ◽  
Author(s):  
W. L. Costin ◽  
I. H. Brown ◽  
L. Green ◽  
R. Ghomashchi
Keyword(s):  
Residual Stresses ◽  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Ion Beam ◽  
Base Material ◽  
Welding Process ◽  
Cold Cracking ◽  
Predictive Methods ◽  
Residual Strains

Hydrogen assisted cold cracking (HACC) is a welding defect which may occur in the heat affected zone (HAZ) of the base metal or in the weld metal (WM). Initially the appearance of HACC was associated more closely with the HAZ of the base metal. However, recent developments in advanced steel processing have considerably improved the base material quality, thereby causing a shift of HACC to the WM itself. This represents a very serious problem for industry, because most of the predictive methods are intended for prevention of HACC in the HAZ of the base metal, not in the weld metal [1]. HACC in welded components is affected by three main interrelated factors, i.e. a microstructure, hydrogen concentration and stress level [2–4]. In general, residual stresses resulting from the welding process are unavoidable and their presence significantly influences the susceptibility of weld microstructures to cracking, particularly if hydrogen is introduced during welding [5]. Therefore various weldability tests have been developed over the years which are specifically designed to promote HACC by generating critical stress levels in the weld metal region due to special restraint conditions [4, 6–8]. These tests were used to develop predictive methods based on empirical criteria in order to estimate the cracking susceptibility of both the heat-affected zone and weld metal [4]. However, although the relationship between residual stress, hydrogen and HACC has received considerable attention, the interaction of residual stresses and microstructure in particular at microscopic scales is still not well understood [5, 9–21]. Therefore the current paper focuses on the development and assessment of techniques using Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction for the determination of local residual strains at (sub) micron scales in E8010 weld metal, used for the root pass of X70 pipeline girth welds, and their relationship to the WM microstructure. The measurement of these strains could be used to evaluate the pre-existing stress magnitudes at certain microstructural features [22].

scholarly journals PENGARUH MEDIA PENDINGINAN TERHADAP KEKERASAN DAN STRUKTUR MIKRO HASIL PENGELASAN OXY ACETYLENE PADA MATERIAL BAJA ST-37

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Made Angga Priadi ◽  
I Nyoman Pasek Nugraha ◽  
Gede Widayana
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Quantitative Research ◽  
Welding Process ◽  
Air Cooling ◽  
Water Cooling ◽  
Independent Variable ◽  
The Mean ◽  
Cooling Media

Media pendingin merupakan suatu substansi yang berfungsi dalam menentukan kecepatan pendinginan yang dilakukan terhadap material yang telah diuji dalam perlakuan panas. Penelitian ini bertujuan untuk mengetahui tingkat kekerasan dan pengamatan struktur mikro material baja ST-37 yang dipengaruhi media pendinginan air, udara dan oli serta penelitian ini dapat memberikan bahan referensi bagi lingkup pendidikan teknik mesin dan sebagai acuan di dunia industri dalam menggunakan media pendingin pada proses pengelasan. Adapun jenis metode yang digunakan dalam penelitian ini adalah metode penelitian eksperimen. Terdapat dua jenis variable yang digunakan dalam penelitian ini yaitu variabel bebas yang berupa media pendingin air, media pendingin udara dan media pendingin oli dan variabel terikatnya berupa sifat kekerasan. Dari hasil penelitian yang telah dilakukan dimana kekerasan daerah logam induk dengan media pendingin air memperoleh nilai rata-rata sebesar 63,10 Kg/mm2, pendingin udara memperoleh nilai rata-rata sebesar 65,61 Kg/mm2, dan media pendingin oli memperoleh nilai rata-rata sebesar 62,68 Kg/mm2. Kekerasan pada daerah HAZ dengan media pendingin air memperoleh nila rata-rata sebesar 68,49 Kg/mm2, media pendingin udara memperoleh nilai rata-rata sebesar 71,05 Kg/mm2 dan media pendingin oli memperoleh nilai rata-rata sebesar 70,34 Kg/mm2. Kekerasan pada daerah logam las dengan media pendingin air memperoleh nilai rata-rata sebesar 60,99 Kg/mm2, media pendingin udara memperoleh nilai rata-rata sebesar 61,79 Kg/mm2 dan media pendingin oli memperoleh nilai rata-rata sebesar 60,79 Kg/mm2. Berdasarkan dari hasil yang telah didapatkan baik pada logam induk, daerah HAZ dan logam Las dimana tingkat kekerasan yang lebih baik diperoleh dari proses pendinginan udara dibandingkan dengan media pendingin air dan media pendingin oli dari proses pengelasan oxy acytelene.Kata Kunci : Baja ST-37, Kekerasan Material, media pendinginan. The cooling media is a substance which has a function to determine the speed refrigeneration which carried out of the material that has been tasted by heat treatment. The objective of the research is to know the level of hardness and the observation of steel ST-37 material which is affected by cooling media such as water, air, and oil. Also this research may give a reference for Engineering Department of Education and industry in using cooling media for welding process. There is a method that use in this research, that is called quantitative research. There are two variables that use in this research. Independent variable and dependent variable. An independent variable are water, air, and oil cooling media. On the other hand, a dependent variable is nature of hardness. In this research the researcher got a results where the mean of hardness of the base metal area with the water cooling media is 63.10 Kg/mm2, in air conditioning is 61Kg/mm2, and the oil cooling is 62.68 Kg/mm2. The mean of a hardness in Heat Affected Zone (HAZ) by water cooling media 68,49 Kg/mm2, air cooling media is 71,05 Kg/mm2 and an air cooling is 70,34 Kg/mm2. The mean of Hardness in the weld metal area with water cooling media is 60,99 Kg/mm2, air-cooling media is 61,79 Kg/mm2 and oil-cooling media is 60,79Kg/mm2. Based on the result which has been gotten from base metal, Heat Affected Zone (HAZ), and weld metal where the best hardness level is obtained from air-cooling process rather than water cooling media and oil cooling media from oxy acytelene welding process.keyword : Cooling media, steel ST-37, hardness properties.

The Effect of Double Pass GMAW Process on Microstructure and Mechanical Properties of Aa 6061-T6 Joining Plates

2012 ◽  
Vol 510-511 ◽  
pp. 98-104 ◽  
Author(s):  
S.R.S. Bakar ◽  
M.Y. Ahmad ◽  
Muhammad Faizol Ahmad Ibrahim ◽  
A. Jalar ◽  
S.J.S. Djalil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Base Metal ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Double Pass ◽  
Metal Solidification ◽  
Microstructure And Mechanical Properties ◽  
First Pass ◽  
Welding Technique

This paper presents an investigation on microstructure and mechanical properties of welded AA 6061-T6 plate using filler metal ER 4043 in the Gas Metal Arc Welding (GMAW) process. Double pass welding technique on both sides of 5 mm thick plate or more is required to provide sufficient weld pool in the joint. The weld metal of the first welding pass exhibits finer microstructure than the second welding pass. The size of Mg2Si precipitations in the heat-affected zone (HAZ) region is larger than in the base metal due to the welding process that reheats the alloy from the T6 condition above the eutectic temperature. Rapid cooling of the first pass and moderate cooling rate for the second pass during weld metal solidification eventually resulted in significantly change the shape and size in the microstructure that had affected the hardness and mechanical properties. Comparisons made to the base metal on the hardness test results found that the hardness of first pass weld metal dropped by 15%, and by 37.5% for the second weld metal, while the hardness at the boundaries of the first and second weld metals dropped by 32.5%. The ultimate tensile strength and strain of the weld joint with ER 4043 also decreased by 48% and 94% respectively. Based on the findings of the study, it is concluded that even though the double sided welding technique is able to overcome shallow weld penetration to avoid stress concentration that leads to the fatigue failure, the metallurgical changes eventually contributes to degradation of mechanical properties.

scholarly journals Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Wenhao Wu ◽  
Ming Zhao ◽  
Haiyan Wang ◽  
Yanxia Zhang ◽  
Tong Wu
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Arc Welding ◽  
Production Efficiency ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Metal Arc Welding ◽  
X80 Steel

Twin-Wire Pulsed Tandem Gas Metal Arc Welding process with high welding production efficiency was used to join the girth weld seam of API X80 steel linepipe of 18.4 mm wall thickness and 1422 mm diameter. The macrostructure, microstructure, hardness, and electrochemical corrosion behavior of welded joints were studied. Effects of temperature and Cl− concentration on the corrosion behavior of base metal and weld metal were investigated. Results show that the welded joint has good morphology, mechanical properties, and corrosion resistance. The corrosion resistance of both the base metal and the weld metal decreases with increasing temperature or Cl− concentration. In the solution with high Cl− concentration, the base metal and weld metal are more susceptible to pitting. The corrosion resistance of the weld metal is slightly lower than that of the base metal.

Microstructure and fatigue behaviour of spin-arc welded AISI C1018 low carbon steel

2021 ◽  
pp. 095440892110277
Author(s):  
K Parthiban ◽  
S Mohan Kumar ◽  
A Rajesh Kannan ◽  
N Siva Shanmugam ◽  
K Sankaranarayanasamy
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Fatigue Behaviour ◽  
Steel Plates ◽  
Low Carbon

This work investigates the fatigue performance of 10 mm AISI C1018 low carbon steel plates welded with ER70S-6 using a gas metal arc welding-based spin-arc welding process. Welded joint microstructure is characterized by bainite, acicular ferrite, and allotriomorphic ferrite along with pearlite in the ferritic matrix. The tensile strength of the weld metal was comparable with base metal and meets the mechanical property requirements in accordance with the ASTM A311/A311M-04 (2020) standard. The fatigue strengths of base metal and weld metal are 121 and 126 MPa, respectively, after sustaining 106 cycles. During cyclic loading, fracture surfaces were distinctly noticed as the crack initiation, crack propagation, and final rupture regions. The decrease in alternating stress increased the fatigue cycles to final rupture, and the nature of fatigue fracture was ductile with dimples and voids.

Effect of shielding gas combination on microstructure and mechanical properties of MIG welded stainless steel 316

2021 ◽  
Vol 63 (1) ◽  
pp. 97-101
Author(s):  
İsmail Açar ◽  
Behçet Gülenç
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Welding Process ◽  
Bending Test ◽  
Welding Parameters ◽  
Microstructural Properties ◽  
Shielding Gas

Abstract The quality of welded joints depends on the most optimal welding parameters and the selection of shielding gas type. The shielding gas was selected for joining stainless steels through gas metal arc welding methods by considering properties such as chemical-metallurgical interaction of shielding gas and the molten weld metal during the welding process, heat transmission capability of the gas and cost. In this study, the effect of different shielding gas combinations on the mechanical and microstructural properties of 316 austenitic stainless steel joined by the metal inert gas (MIG) welding method was investigated. In the welding process, pure argon (100 % Ar), 98.5 % Ar + 1.5 % H2 and 95 % Ar + 5 % H2 were used as shielding gases. Tensile, hardness, and bending tests were conducted to determine mechanical properties of the welded samples. In addition, metallographic examinations were carried out to detect the macrostructural and microstructural properties of weld zones. According to the results obtained from the study, the highest tensile strength was obtained from the joints welded using 100 % Ar shielding gas. When the addition of H2 into the Ar gas increased, the tensile strength of the welded samples decreased. As a result of the tensile test, fractures occurred in the base metal in all welded samples. In all welding parameters, the hardness of the weld metal was lower as compared to the heat affected zone (HAZ) and the base metal. As a result of the bending test, crack and tearing defects were found in the weld zone.

Microstructure and Properties of X100 High Strength Pipeline Steel

2015 ◽  
Vol 814 ◽  
pp. 325-332 ◽  
Author(s):  
Yu Xiao Tian ◽  
Bin Wang ◽  
Jun Liang Li ◽  
Bo Li Chen ◽  
Quan Feng
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Weld Joint ◽  
Pipeline Steel ◽  
Testing Machine ◽  
Welding Process ◽  
Test Machine ◽  
Tensile Testing Machine ◽  
Microstructure And Properties ◽  
The Impact

In order to study the effect of welding process on the microstructure and properties of weld joint of X100 pipeline steel, GMAW was used to prepare the weld joint with low-carbon high manganese-molybdenum-nickel flux cored welding wire. SEM and XRD were used to analyze the microstructure and phase morphology of HAZ and weld metal. Hydraulic tensile testing machine and impact test machine were used to test the mechanical properties. The experimental results showed that the weld metal and HAZ were composed of bainite, ferrite and M/A, the microstructure was fine and uniform with columnar crystal morphology, and HAZ was quite coarse. Hardness of weld metal was 248HV, which is higher than that of base metal, however, HAZ was softening. The tensile strength of weld joint was 832Mpa, which is about 96% of the base metal. The impact absorbed energy at-20°C of the base metal and weld metal were 291J and 121J respectively, exhibiting excellent strength and toughness.

NIMROD 617KS

Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Weld Metal ◽  
Tensile Properties ◽  
Base Metal ◽  
Heat Treating ◽  
Nominal Composition

Abstract Nimrod 617KS is an Inconel-type consumable with a nominal composition of nickel, 24% Cr,12% Co, and 9% Mo and is used to join UNS N06617 and Nicrofer 6023 to themselves. The alloy is designed for high-temperature service and is often used as the weld metal in dissimilar cases to ensure the weld is as strong as the base metal. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and joining. Filing Code: Ni-583. Producer or source: Metrode Products Ltd.

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