Effect of Corrosion of Stainless Steel Welded within Lithium Chloride

2016 ◽  
Vol 869 ◽  
pp. 470-473
Author(s):  
Juliete N. Pereira ◽  
David Márcio Macêdo Dias ◽  
Natal Nerímio Regone ◽  
Marcos A. Fernandes ◽  
Sandra Nakamatsu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Lithium Chloride ◽  
Welding Process ◽  
Weld Bead ◽  
Mechanical Resistance ◽  
Martensitic Steels ◽  
Cyclic Potentiodynamic Polarization ◽  
Lithium Chloride Solution ◽  
Welding Processes

The difficulties experienced in welding processes of martensitic stainless steel led to development of a new class of them, known as stainless mild martensitic steels. Also, due to the current high demand for energy and materials to oil extraction at great depths, scientists have being developing specific researches about mechanical resistance and corrosion of steels and how these properties are influenced by high temperature processes. This research studies the effect of welding process over the corrosion resistance of the 13Cr4Ni0.02C steel in a lithium chloride solution with a concentration of 120,000 PPM Cl-. The corrosion tests were conducted by cyclic potentiodynamic polarization in the base metal, weld bead and heat affected zone (HAZ) areas of the steel, in average temperatures of 23°C (as reference) and 3°C. The results revealed that the weld bead and heat affected zones of the 13Cr4Ni0.02C steel in a temperature of 3°C are less resistant to corrosion in this environment than the base metal in the same conditions.

Multi-criteria optimization of weld bead in pulsed Nd:YAG laser welding of stainless steel 316

2018 ◽  
Vol 233 (2) ◽  
pp. 151-164 ◽  
Author(s):  
Ali Solati ◽  
Nasrollah Bani Mostafa Arab ◽  
Akbar Mohammadi-Ahmar ◽  
Hamid Reza Fazli Shahri
Keyword(s):  
Stainless Steel ◽  
Laser Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Quality Criteria ◽  
Optimization Procedure ◽  
Weld Bead ◽  
Micro Hardness ◽  
Pulsed Nd:Yag Laser Welding ◽  
Welding Processes

Laser welding is widely used for its advantages like deeper weld penetration, narrow heat affected zone, higher welding speeds and better weld quality with less damage to the workpiece compared to arc welding processes. The purpose of this paper is to determine the influence of major laser welding process parameters of beam pulse energy, travel speed and focal position on weld fusion zone geometry in stainless steel and optimizing these parameters to obtain maximum penetration and minimum weld width simultaneously. The experiments were planned according to Taguchi’s L16 orthogonal array. The grey-based Taguchi method was then employed to convert the multiple quality criteria into one single relational grade. Based on the calculated relational grade, Taguchi tools such as analysis of variance and signal-to-noise ratio were used to analyze and obtain the significant parameters and evaluate the optimum combination levels of the mentioned process parameters. Moreover, the effect of optimization procedure was studied on the microstructure and micro-hardness of the weldments. It was concluded that this optimization method can lead to elimination of chain ferrite precipitation and more uniform micro-hardness across the weld bead. The confirmation experiments verified that this method can effectively improve multiple performance characteristics and the results are reproducible in laser welding.

scholarly journals Influence of Molybdenum on Microstructure and Pitting Corrosion Behavior of Solution-Treated Duplex Stainless Steel in a Lithium Chloride Solution

2019 ◽  
Vol 22 (suppl 1) ◽  
Author(s):  
Stephania Cappellari de Rezende ◽  
Isabela Dainezi ◽  
Raíra Chefer Apolinario ◽  
Lucíola Lucena de Sousa ◽  
Neide Aparecida Mariano
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Lithium Chloride ◽  
Pitting Corrosion ◽  
Chloride Solution ◽  
Solution Treated ◽  
Lithium Chloride Solution

scholarly journals Experimental and Numerical Analysis on TIG Arc Welding of Stainless Steel Using RSM Approach

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1659
Author(s):  
Sasan Sattarpanah Karganroudi ◽  
Mahmoud Moradi ◽  
Milad Aghaee Attar ◽  
Seyed Alireza Rasouli ◽  
Majid Ghoreishi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Welding Speed ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Bead Geometry ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width

This study involves the validating of thermal analysis during TIG Arc welding of 1.4418 steel using finite element analyses (FEA) with experimental approaches. 3D heat transfer simulation of 1.4418 stainless steel TIG arc welding is implemented using ABAQUS software (6.14, ABAQUS Inc., Johnston, RI, USA), based on non-uniform Goldak’s Gaussian heat flux distribution, using additional DFLUX subroutine written in the FORTRAN (Formula Translation). The influences of the arc current and welding speed on the heat flux density, weld bead geometry, and temperature distribution at the transverse direction are analyzed by response surface methodology (RSM). Validating numerical simulation with experimental dimensions of weld bead geometry consists of width and depth of penetration with an average of 10% deviation has been performed. Results reveal that the suggested numerical model would be appropriate for the TIG arc welding process. According to the results, as the welding speed increases, the residence time of arc shortens correspondingly, bead width and depth of penetration decrease subsequently, whilst simultaneously, the current has the reverse effect. Finally, multi-objective optimization of the process is applied by Derringer’s desirability technique to achieve the proper weld. The optimum condition is obtained with 2.7 mm/s scanning speed and 120 A current to achieve full penetration weld with minimum fusion zone (FZ) and heat-affected zone (HAZ) width.

scholarly journals Comparative in Mechanical Behavior of 6061 Aluminum Alloy Welded by Pulsed GMAW with Different Filler Metals and Heat Treatments

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4157 ◽  
Author(s):  
Isidro Guzmán ◽  
Everardo Granda ◽  
Jorge Acevedo ◽  
Antonia Martínez ◽  
Yuliana Dávila ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Weld Joint ◽  
Welding Process ◽  
Mechanical Resistance ◽  
6061 Aluminum Alloy ◽  
Β Phase ◽  
Welding Processes ◽  
Filler Metals

Precipitation hardening aluminum alloys are used in many industries due to their excellent mechanical properties, including good weldability. During a welding process, the tensile strength of the joint is critical to appropriately exploit the original properties of the material. The welding processes are still under study, and gas metal arc welding (GMAW) in pulsed metal-transfer configuration is one of the best choices to join these alloys. In this study, the welding of 6061 aluminum alloy by pulsed GMAW was performed under two heat treatment conditions and by using two filler metals, namely: ER 4043 (AlSi5) and ER 4553 (AlMg5Cr). A solubilization heat treatment T4 was used to dissolve the precipitates of β”- phase into the aluminum matrix from the original T6 heat treatment, leading in the formation of β-phase precipitates instead, which contributes to higher mechanical resistance. As a result, the T4 heat treatment improves the quality of the weld joint and increases the tensile strength in comparison to the T6 condition. The filler metal also plays an important role, and our results indicate that the use of ER 4043 produces stronger joints than ER 4553, but only under specific processing conditions, which include a moderate heat net flux. The latter is explained because Mg, Si and Cu are reported as precursors of the production of β”- phase due to heat input from the welding process and the redistribution of both: β” and β precipitates, causes a ductile intergranular fracture near the heat affected zone of the weld joint.

Role of welding processes on microstructure and mechanical properties of nuclear grade stainless steel joints

2019 ◽  
Vol 233 (11) ◽  
pp. 2335-2351 ◽  
Author(s):  
R Rajasekaran ◽  
AK Lakshminarayanan ◽  
M Vasudevan ◽  
P Vasantharaja
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Nuclear Grade ◽  
Lower Percentage ◽  
Weld Joints ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Welding Processes

Nuclear grade 316LN austenitic stainless steel weld joints were fabricated using conventional gas tungsten arc welding (GTAW), activated flux gas tungsten arc welding (AGTAW), laser beam welding (LBW) and friction stir welding (FSW) processes. Assessment of weld beads was done by mechanical and metallurgical characterizations. Bead geometry and weld zones were studied by taking macrographs along the transverse side of the weld joints. Metallurgical features of different weld joints were carried out using optical microscopy and scanning electron microscopy. Microhardness distribution across four weld joints was recorded and hardness variations were compared. All weld zone, heat affected zone (HAZ) of GTAW and LBW, thermo-mechanically affected zone (TMAZ) of FSW processes, exhibited higher hardness values than the base metal. Reduced hardness was recorded at HAZ of AGTAW process. This was the result of a considerable grain growth. LBW joint showed the highest hardness value at the center of the fusion zone due to fine equiaxed dendrite morphology. Tensile and impact properties of different welding processes were evaluated and comparisons were made at room temperature. All weld samples displayed high yield strength (YS) and ultimate tensile strength (UTS) with a lower percentage of elongation compared to that of the base metal. FSW joint showed improved YS, UTS and impact toughness compared to other weld joints. This is attributed to the formation of strain-free fine equiaxed grains at stir zone around 5 µm in size with subgrains of 2 µm in size by severe dynamic recrystallization mechanism. Among the fusion welding techniques, AGTAW process exhibited improved toughness, besides almost equal toughness of the base metal due to low δ-Ferrite with high austenite content. Fractography studies of the base metal and different weld samples were carried out by SEM analysis and features were compared.

Phenomenological Modeling of Fusion Welding Processes

MRS Bulletin ◽  
1994 ◽  
Vol 19 (1) ◽  
pp. 29-35 ◽  
Author(s):  
S.A. David ◽  
T. DebRoy ◽  
J.M. Vitek
Keyword(s):  
Solid State ◽  
Heat Source ◽  
Base Metal ◽  
Weld Pool ◽  
Welding Process ◽  
Poor Performance ◽  
Consumer Products ◽  
Phase Changes ◽  
Fusion Welding ◽  
Welding Processes

Welding is utilized in 50% of the industrial, commercial, and consumer products that make up the U.S. gross national product. In the construction of buildings, bridges, ships, and submarines, and in the aerospace, automotive, and electronic industries, welding is an essential activity. In the last few decades, welding has evolved from an empirical art to a more scientifically based activity requiring synthesis of knowledge from various disciplines. Defects in welds, or poor performance of welds, can lead to catastrophic failures with costly consequences, including loss of property and life.Figure 1 is a schematic diagram of the welding process showing the interaction between the heat source and the base metal. During the interaction of the heat source with the material, several critical events occur: melting, vaporization, solidification, and solid-state transformations. The weldment is divided into three distinct regions: the fusion zone (FZ), which undergoes melting and solidification; the heat-affected zone (HAZ) adjacent to the FZ, that may experience solid-state phase changes but no melting; and the unaffected base metal (BM).Creating the extensive experimental data base required to adequately characterize the highly complex fusion welding process is expensive and time consuming, if not impractical. One recourse is to simulate welding processes either mathematically or physically in order to develop a phenomenological understanding of the process. In mathematical modeling, a set of algebraic or differential equations are solved to obtain detailed insight of the process. In physical modeling, understanding of a component of the welding process is achieved through experiments designed to avoid complexities that are unrelated to the component investigated.In recent years, process modeling has grown to be a powerful tool for understanding the welding process. Using computational modeling, significant progress has been made in evaluating how the physical processes in the weld pool influence the development of the weld pool and the macrostructures and microstructures of the weld.

Laser Welding Simulations of Stainless Steel Joints Using Finite Element Analysis

2011 ◽  
Vol 383-390 ◽  
pp. 6225-6230
Author(s):  
K.R. Balasubramanian ◽  
T. Suthakar ◽  
K. Sankaranarayanasamy ◽  
G. Buvanashekaran
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Laser Beam ◽  
Laser Welding ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Heat Of Fusion ◽  
T Joints ◽  
Finite Element Software

Laser beam welding (LBW) is a fusion joining process that uses the energy from a laser beam to melt and subsequently crystallize a metal, resulting in a bond between parts. In this study, finite element method (FEM) is used for predicting the weld bead profile of laser welding butt, lap and T-joints. A three-dimensional finite element model is used to analyze the temperature distribution weld bead shape for different weld configurations produced by the laser welding process. In the model temperature-dependent thermo physical properties of AISI304 stainless steel, effect of latent heat of fusion and convective and radiative boundary conditions are incorporated. The heat input to the FEM model is assumed to be a 3D conical Gaussian heat source. The finite element software SYSWELD is employed to obtain the numerical results. The computed weld bead profiles for butt, lap and T-joints are compared with the experimental profiles and are found to be in agreement.

Study on Local Dry Welding of 304 Stainless Steel in Nuclear Power Stations Repair

2012 ◽  
Vol 460 ◽  
pp. 415-419 ◽  
Author(s):  
Can Feng Zhou ◽  
Xiang Dong Jiao ◽  
Jia Lei Zhu ◽  
Hui Gao ◽  
Qiu Ping Shen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Water Depth ◽  
Nuclear Power ◽  
Test Chamber ◽  
Welding Process ◽  
304 Stainless Steel ◽  
Underwater Welding ◽  
Power Stations ◽  
Welding Processes ◽  
Cladding Layers

Local dry welding is an important water welding method with special advantages for good flexibility in nuclear power stations repair where operation spaces are usually very limited, and it can be applied perfectly by simple integration of a lot of welding processes with shielding cup. An underwater welding system chamber was built, which is mainly comprised of an underwater welding test chamber, and a hydraulic driven underwater welding device. Shielding gas is inflated to the small compacted cup to drive water and protect arc and weld pool. At shallow water of 100mm,Pulsed MIG tests were carried out to investigate parameters which are related to welding process of 304 stainless steel cladding layers. Welding tests at different depth indicates that although profiles of welds produced both at pressures of 5 meters water depth and at pressures of 15 meters water depth are perfect, but cladding layer at 15 meters is more narrow and more high

Qualification of Laser Welded High Performance S44660 Ferritic Stainless Steel for Condenser Tube Applications

2003 ◽  
Author(s):  
James D. Fritz ◽  
Curtis W. Kovach
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
High Performance ◽  
Sheet Material ◽  
Cooling Water ◽  
Welding Process ◽  
Gas Tungsten Arc ◽  
Critical Pitting Temperature ◽  
Gas Tungsten ◽  
Welding Processes

The laser tube welding process has for the first time been used to produce power plant steam condenser tubing in the high performance ferritic stainless steel grade UNS S44660. This material has traditionally been produced as welded tubing by the gas tungsten-arc welding process for use in seawater and other severe cooling water environments. To verify the corrosion resistance of this new product, corrosion tests have been conducted on production tubing to compare the traditional and new welding processes. The acidified ferric chloride test was used for evaluation because it is a meaningful aggressive test capable of measuring resistance to localized pitting corrosion, the most common potential failure mode for stainless steels used in cooling water environments. Pitting tests conducted over a range of temperatures produced a critical pitting temperature of 65°C for laser welded-annealed tube. This critical pitting temperature was demonstrated to be equal to that of as-produced S44660 sheet material or that of gas tungsten-arc produced tubing. The tubing met all other metallurgical and mechanical property quality requirements. When pitting did occur it exhibited no preference for initiation at welds. Thus, laser welded. high performance stainless condenser tubing should be fully capable of providing good performance in severe cooling water environments.

scholarly journals Welding Soundness of a Thick-Walled 9Cr-1Mo Steel

2010 ◽  
Vol 654-656 ◽  
pp. 408-411
Author(s):  
Woo Seog Ryu ◽  
Sung Ho Kim ◽  
Dae Whan Kim
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Base Metal ◽  
Hardness Test ◽  
Ultimate Tensile Stress ◽  
Narrow Gap ◽  
Martensitic Steels ◽  
Narrow Gap Welding ◽  
Self Energy ◽  
Welding Processes

High Cr ferritic/martensitic steels are demanded to join using favorable welding processes with economical and metallurgical advantages in order to apply to the thick-walled reactor pressure vessel of a very high temperature gas cooled reactor. Narrow gap welding technology was adopted to weld a thick-walled 9Cr-1Mo-1W steel with thickness of 110mm. The welding integrity was checked by non-destructive examination, optical microscopy and hardness test, and the homogeneity through welding depth was checked by absorbed impact energy and tensile strength. The optimizing welding conditions resulted that a narrow U-grooved gap with almost parallel edges was sound in actual practice, and the coarse grain zone was minimized in the heat affected zone. The absorbed energy of 75±25 J through welding depth was acceptable in scatter band to check the uniformity through the welding depth. The ultimate tensile stress and yield stress were about the same through welding depth at 650±10 MPa and 500±10 MPa, indicating no difference through welding depth. Elongation was also almost same through depth, and the fracture surface was appeared as a normal. The weld metal had similar mechanical properties to base metal. The upper self energy of weld metal was 194J, and the ductile-brittle transition temperature was 30°C. The tensile behavior was the typical trend with temperature, and YS and UTS of weldment were slightly higher than base metal by nearly below 10%. Thus, it concluded that the soundness of the narrow gap welding of a thick-walled 9Cr-1Mo-1W steel was confirmed in terms of the welding uniformity through the depth and mechanical properties.

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