Similar Metal Weld Research Articles

Recent developments in tensile properties of friction welding of carbon fiber-reinforced composite: A review

Abstract In this review article, the joining of carbon fiber-reinforced polymer composite with metallic materials by using friction welding techniques was discussed and the effects of process parameters on the weld properties were evaluated. Major parameters involved in this process were plunge depth (PD), dwell time, joining time, and tool rotational speed. A successful friction joint of carbon fiber-reinforced poly composite laminate (CF-PPS)-metal was formed with an interlayer film of additional polyphenylene sulfide. In addition, a detailed overview of the friction techniques was discussed, such as friction stir spot welding (FSSW), friction stir welding (FSW), and refill friction stir spot welding (RFSSW). In this current work, we had focused on the parameters, process, and their development during friction welding of similar and dissimilar metals with CFRP joint. Regarding the FSSW review, the best tensile shear load was 7.1 kN obtained from AA5182 and CFRP at a rotational speed of 3,000 rpm and 5 s welding time. The thickness for AA5182 and CFRP are 1.2 and 3 mm, respectively. The most efficient parameters are rotational speed, PD, dwell time, and shoulder penetration depth. In addition, the heat generated during the process parameters, its influence on mechanical and microstructure properties along with the possible defects and internal cracks of the similar and dissimilar welded joints will be reviewed and discussed.

Variant of MIG welding of similar and dissimilar metals: A review

Most of the steel and aluminium based alloys can be welded by MIG welding process as it gives better mechanical properties and microstructure at optimized input parameters. Various researchers experimentally analysed the suitability of MIG welding for joining of wide range of alloys used in various applications. Process parameters of MIG welding are the important factors that influence the quality of the weld. The purpose of this review paper is to summarize the published literature related to different variants of MIG welding and to observe the influence of various input process parameters of MIG welding on microstructure, hardness, tensile strength and impact strength of the weldment. Results revealed that change in value of any of the parameters can significantly affect the weld properties. Welding current and welding speed are the most important among the principal input welding parameters. Lower welding voltage and gas flow rate and higher welding speed and wire feed rate results maximum ultimate tensile strength of the weldment. Better mechanical properties and reduced residual stresses obtained during Pulsed MIG as compared to conventional MIG or MAG welding. There is a better scope of research on mechanism of residual stresses and their correlation with microstructure and mechanical properties to improve the weld quality.

Oxidation Behavior of Welded Fe-Based and Ni-Based Alloys in Supercritical CO2

Next-generation supercritical CO2 (sCO2) power cycles will require different classes of alloy throughout the operational temperatures to optimize tradeoff of creep strength, oxidation performance and cost. This will necessitate joining methods such as welding, which might pose compatibility concerns at the joined interfaces. In this study, similar and dissimilar metal welds were generated from a variety of candidate alloys for sCO2 systems including ferritic/martensitic steels, austenitic steels, and Ni-based superalloys. Samples were extracted from different regions of the welds and exposed to sCO2 at 550 °C and 20 MPa for 2500 h and then characterized to understand their behavior in this environment. Unsurprisingly, the local oxidation behavior was largely dictated by the Cr content in the underlying metal. High-Cr austenitic steels and Ni alloys formed slow-growing Cr-rich oxide scales with minimal carburization of the underlying metal, while low-Cr ferritic/martensitic steels formed fast-growing Fe-rich oxide scales with significant carburization. Most welds did not show any unusual oxidation behavior at the interfaces, considering the local Cr content. The one exception was the 347H similar metal weld, where a larger grain size and complex grain structure in the fusion zone led to a significantly higher rate of Fe-rich oxide nodule formation compared to the base metal. This suggests that microstructural changes at joined interfaces can play an important role on the oxidation-limited lifetimes in future sCO2 systems. The composition changes across the interfaces enabled study of the effect of Fe on the growth rate of Cr-rich oxides and of the origins of the subsurface recrystallization zone that forms beneath them.

Cyclic Ramberg–Osgood Parameters of 316SS Weld Metal Under In-Air and PWR-Water Environments

Abstract At present, the available Ramberg–Osgood (R–O) parameters for different metals (e.g., in ASME code and other literatures) are static (generally based on a tensile curve). These static R–O parameters cannot accurately model the cyclic plasticity behavior. This work presents the cyclic R–O material hardening parameters for 316 stainless steel similar metal welds. The parameters were estimated under various conditions (in-air at room temperature, 300 °C in-air, and in-air at primary water conditions for a pressurized water reactor (PWR)). It is anticipated that the reported results would be useful for computational mechanics-based shakedown analysis and fatigue life estimation of PWR components.

Finite element analysis of lap joint based on various geometrical parameters to study the behavior of weld strength

This paper reports on study of lap joint weld shear strength of resistance spot weld. Resistance Spot Welding (RSW) is a very cost effective joining technology in automobile industry used to join sheets or plates. The research papers present the effect of various parameters like welding time, welding current, electrode force and squeeze time on strength of joint formed by spot welding of similar and dissimilar metals and thicknesses. Optimization of these parameters is obtained by the micro-hardness test, tensile shear test and fatigue test and the papers presented the methodologies to increase the fatigue life of the joint. In this paper MSC Nastran software is used to analyze the strength of the joint formed by the resistance spot welding. Steel Plates or sheets are modeled with Shell elements of type CQUAD4 and weld element between two plates (Nuggets) are modeled with 1D element with CBAR elements. Various FE models are generated with the consideration of geometrical parameters like thickness of the plate, nuggets along the span length and edge distance. FE models will be subjected to constant pre-defined loads on the various FE models and the weld shear strength were captured for each model and compared against the other models to study the weld behavior. Outcome of the present study provides the insight towards the selection of the optimized weld spots (nuggets) distribution for the various thicknesses of the plate, location of the nuggets along the length and the selection of optimum edge distance. The present study is used to compare the stresses induced in the plates and nuggets for the given load.

Research contribution and potential investigation on friction stir welding for AA2014 material family

Abstract Aluminum alloy 2014 has wide application. In its applications, aerospace and automobile industries are utilized well such Aluminum alloy. This article presents a novel approach of reviewing material related research to pave the path for new researchers. The aluminum is one of the popular materials and can be modified either to form a composite or augmenting the material properties with utilization of heat treatment methods. Friction stir welding is one of the advanced metals joining/ welding technology. This paper reviews how the two popular cases jointly contributing for creating mechanical structures. This papers covers parameter optimizations for friction stir welding of similar and dissimilar metals, mathematical modeling, post welding treatments, new tool contributions, grain structure effects, need for FSW and identified further research scope further research are consolidated and presented as research potential.

Resistance Spot Welding of Similar and Dissimilar Metals: The Effect of Graphene Interlayer

Resistance spot welding of similar AISI-1008 steel plates and dissimilar AISI-1008/Al-1100 alloy joints were carried out using a graphene nanoplatelets interlayer and the underlying strengthening mechanisms were discussed. Weld strength of the joints depends on the welding current/time used for the resistance spot welding. An enhancement of ~ 49% and ~ 124% was reported at certain parameters for the similar and dissimilar joints, respectively. Optical microscopy, SEM, XRD, TEM and Raman spectroscopy was used for microstructural characterization. Microhardness studies at the weld nugget cross-section revealed an enhanced hardness at the fused zone for both the cases. Al-Fe rich intermetallics formation was reported at the interfacial zone of the dissimilar joints which played a role in hardness increment. Variation of nugget size with the increase in welding current was studied. Fractured surfaces were analyzed and it was concluded that shear dimple and a mix of the shear dimple and brittle fractures were dominant in cases of similar and dissimilar metal joints, respectively.

Study and evaluation of cold joining on metals and non metals combinations (ss, al, acr) using polymer based adhesive

The world innovated the different generation and different joining process for fabricating the metals using different methods. It reaches the ultimate level in the welding of similar and dissimilar metals, in different phases also. All joining processes, proofs its mechanical properties. But, the metal joining methods are in a condition to change to compete in market. So that now a day’s metal joining methods take a different move towards polymer based epoxy adhesive cold welding process. This epoxy is the convenient alternative for cold welding of metals, and nonmetals. The mechanism of bonding is mutually reactive chemical groups with coupling agent create chemical bonds and adhere the both materials. Based on this concept, this research work is carryout. In this research work combinations of different metals and nonmetals such as Stainless Steel (SS), Aluminium (Al), and Acrylic (ACR) are joined with polymer based epoxy resin, in the background of same metals like SS + SS, AL + Al. ACR + ACR. These combinations of cold joining process were carryout with two conditions, finished condition and roughed condition using A394emery sheet. The adhesive thickness maintained using feeler gauge size of 0.5 mm. This fabrication process were carried out using specially designed and fabricated fixture to avoid misalignments while fabrication. To fine the character and behavior of adhesive welding flexural test were conducted onUTM. The result shows that, on finished condition samples and prove adhesive mechanism character in flexural test by increasing order such as ACR + ACR increases 9.63 times, Al + Al increases 4.82, SS + SS increases 1.54 times.

Process parameter optimization and performance comparison of AISI 430 and AISI 1018 in resistance spot welding process

Resistance spot welding (RSW) process plays an important role in the sheet metal fabrication process, in which metal joining is obtained by heat developed through electric resistance against the current flow in the metals contact area. In this work, the impact of weld time, squeeze time, weld current and hold time on weld strength of 1.2 mm thickness ferritic stainless steel (AISI 430) and low carbon mild steel (AISI 1018) sheets by using RSW process were investigated and compared. The Design of experiment (DoE) was used to formulate the number of experiments with variations in input conditions. Welding of similar metals of AISI 430 and AISI 1018 was done according to the number of experiments obtained using DoE. The welded samples were subjected to tensile shear failure load and micro-hardness testing. The output responses were analyzed through Response surface methodology (RSM) to find the optimum control parameters to achieve higher weld strength.

Effect of weld angle on the creep rupture life of ferritic/austenitic dissimilar weld interfaces under remote mode I fracture

Dissimilar metal welded structures (DMWs) used extensively in conventional and nuclear power plants can suffer from in-service failures at the dissimilar interface with a much reduced life compared to similar metal weld counterparts at the same operating stress and temperature. This paper evaluates the effect of weld angle on the interface creep failure mode of two-dimensional DMW plates consisting of a ferritic steel P91 and an Inconel 82 filler metal within a finite element (FE) framework. A physical cavity growth damage zone model is developed to describe the damage accumulation at the interface, which naturally takes into account the local mode mixity. The material parameters are calibrated against standard 90° weld creep rupture data and used to predict the rupture life of DMWs with a range of axial loads and reduced weld angles (75°, 60°, 45° and 30°). The predicted results match reasonably well with the limited interface failure data for a 45° weld angle. This work also provides additional evidence and insights regarding the improvement of interface creep rupture life of DMWs in power plant pipelines, in particular: (1) Compared with a 45° weld angle, a 60° weld angle is more detrimental to the creep life and should be avoided in actual components – on the contrary, damage tolerance can be promoted by designing and adopting weld angles smaller than 45°, which can have lives exceeding that of standard 90° welded components; (2) A weld interface with alternating weld angles/paths is expected to enable a greater fraction of the creep rupture life to be taken up with crack propagation compared with a flat weld interface, which also increases the probability of damage detection; (3) A fully constrained boundary condition is beneficial to the creep rupture life compared with a free boundary condition; (4) For weld angles less than 90°, the diversion of the crack into the HAZ is less likely compared with a 90° weld angle. Type IV failure mode through the FGHAZ is also less likely to occur.

Experimental Investigation and Process Optimization of DSS/DSS Similar Metal Weld Joint

Abstract This study aims to investigate and optimize the process parameter of similar metal weld joint between Duplex Stainless Steel and Duplex Stainless Steel. Plates of 2 mm thickness of DSS conforming to grade 2205 were butt welded using Gas Tungsten Arc welding, with Argon as shielding gas. Electrode to specification E 309LT-1 was used as filler metal. Test specimens were evaluated for tensile test and the values were observed as ultimate tensile strength 659 Mpa, yield strength 596 Mpa and the breaking load 23.74 KN. Objective of this work is to investigate mechanical properties and to optimize the process parameters to obtain higher tensile values by using Taguchi method. Voltage, Current and filler feed rate were chosen as a control factors in view of the impact on the input variables. Ultimate tensile strength was chosen as response variable to calculate the signal-to-noise ratio. Analysis of variance (Anova) method was adapted to identify the percentage contribution for all the factors and high important factor which is contributing for the optimum result.

Friction Crush Welding of Similar Metals: An Overview

Friction Crush Welding (FCW) is a newly developed technique which can be used for welding of similar materials with or without filler metal. In this process, welding between two work pieces occurs due to relative motion between work pieces and rotating cylindrical tool, which causes crushing of material to produce weld. Similar weld which include welds of aluminium, steel and copper and their alloy have been successfully produced by few researchers. This review covers the work conducted in the field of FCW and throws light on the future use of FCW for welding similar and dissimilar materials.

Microstructure and mechanical properties of similar and dissimilar metal gas tungsten constricted arc welds: Maraging steel to 13-8 Mo stainless steel

Abstract Maraging steel (250) and 13-8 Mo stainless steel plates were joined by gas tungsten constricted arc welding (GTCAW) process in similar and dissimilar metal combinations using 13-8 Mo stainless steel filler wire. The similar and dissimilar metal welds made in solutionized condition were subjected to standard post weld hardening treatments direct ageing at 485 °C, soaking for 3½ hours followed by air cooling (ageing treatment of maraging steel) and direct ageing at 510 °C, soaking for 4 h followed by air cooling (ageing treatment of 13-8 Mo stainless steel). The joint characterization studies include microstructure examination, microhardness survey across the weldments and transverse weld tensile test. Similar and dissimilar metal weldments responded to both the post weld ageing treatment. After post weld aging, increase in yield strength, UTS and slight reduction in % elongation of similar and dissimilar metal were observed. The observed tensile properties were correlated with microstructure and hardness distribution across the welds.

Thermal Model of Rotary Friction Welding for Similar and Dissimilar Metals

Friction welding is one of the foremost welding processes for similar and dissimilar metals. Previously, the process has been modeled utilizing the rudimentary techniques of constant friction and slip-stick friction. The motivation behind this article is to present a new characteristic for temperature profile estimation in modeling of the rotary friction welding process. For the first time, a unified model has been exhibited, with an implementation of the phase transformation of similar and dissimilar materials. The model was generated on COMSOL Multiphysics® and thermal and structural modules were used to plot the temperature curve. The curve for the welding of dissimilar metals using the model was generated, compared and analyzed with that of practical curves already acquired through experimentation available in the literature, and then the effect of varying the parameters on the welding of similar metals was also studied.

The Current Status of New Czech Corrosion Fatigue Evaluation Proposal for WWER Nuclear Power Plants

Presented paper introduces an innovative principle of fatigue life assessment suggested for WWER nuclear power plants. The subject of this work is to take into account the corrosion environment influence in actual methodology of low-cycle fatigue (LCF) assessment and prediction. The aim of this paper is to summarize the current status of the Czech proposal of corrosion fatigue assessment and prediction. The first project focused on base steel materials, which are used in primary circuit of WWER-440, started in 2010. The basic idea of Czech environmental fatigue correction factor has been introduced on international PVP conference in 2013. The new project linked to the previous one is focused on the additional area of welding joints. Theoretical base is completed by experimental verifications of proposed environmental correction factor. The subject of actually running theoretical-experimental program covers similar metal welds of austenitic stainless steel 08CH18N10T and results will be available in 2015. Moreover LCF tests in corrosion environment of dissimilar metal welds are under preparation. Experimental work is based on LCF strain-controlled tests in primary water environment of WWER-440.

STUDY OF MICROSTRUCTURE AND STRESS CORROSION CRACKING BEHAVIOR IN WELDING TRANSITION ZONE OF Ni–BASED ALLOYS

Welding technique is generally used in nuclear power plant for manufacturing and machining important components such as steam generator. The similar metal weld and dissimilar metal weld were commonly involved to connect and fixup tubings in steam generators. However, in recent years large amounts of cracking accidents have been observed in the welded joints. A concern has been raised about the integrity and reliability in the joint transition zone due to the high susceptibility of heat affected zone (HAZ) and fusion zone (FZ) to stress corrosion cracking (SCC). In this study, the similar metal and dissimilar metal joints were investigated and compared, focusing on the correlation between microstructure, residual strain and SCC behavior. The microstructures of transition zone in Ni-based Alloys 690 and 52 similar metal joint and Alloys 182 and A533B low alloy steel dissimilar metal joint were investigated comprehensively by SEM, EBSD, TEM. The residual strain distribution in the HAZ of 690-52 similar metal joint was quantitatively measured. The SCC behavior of 182-A533B dissimilar metal joint in high temperature oxygenated water were simulated by creviced bent beam specimen. The HAZ in the similar joint exhibits higher residual strain, sensitive microstructure and high susceptibility to SCC, therefore, the HAZ region deserve more attention during the inspection and examination of components. The FZ of the dissimilar metal joint exhibits complicated microstructure and chemical

A study of weld quality in ultrasonic spot welding of similar and dissimilar metals

Several difficulties are faced in joining thinner sheets of similar and dissimilar materials from fusion welding processes such as resistance welding and laser welding. Ultrasonic metal welding overcomes many of these difficulties by using high frequency vibration and applied pressure to create a solid-state weld. Ultrasonic metal welding is an effective technique in joining small components, such as in wire bonding, but is also capable of joining thicker sheet, depending on the control of welding conditions. This study presents the design, characterisation and test of a lateral-drive ultrasonic metal welding device. The ultrasonic welding horn is modelled using finite element analysis and its vibration behaviour is characterised experimentally to ensure ultrasonic energy is delivered to the weld coupon. The welding stack and fixtures are then designed and mounted on a test machine to allow a series of experiments to be conducted for various welding and ultrasonic parameters. Weld strength is subsequently analysed using tensile-shear tests. Control of the vibration amplitude profile through the weld cycle is used to enhance weld strength and quality, providing an opportunity to reduce part marking. Optical microscopic examination and scanning electron microscopy (SEM) were employed to investigate the weld quality. The results show how the weld quality is particularly sensitive to the combination of clamping force and vibration amplitude of the welding tip.

Ultrasonic Deposit Junction Characteristic Evaluation of Metal Sheets Al/Al and Al/Cu

This paper describes an experimental study on ultrasonic welding of similar and dissimilar metals. There are optimum welding conditions which are found for welding of Al/Al and Al/Cu. It evaluated weldability using tensile test, SEM observation and EDX-ray analysis. Both ultrasonic welding of Al/Al and Al/Cu have amplitude as the variable factor. Al/Cu welding was examined again with welding time as variable factor to find the best conditions. The more welding time or amplitude increase, the better weldability. The optimum conditions for ultrasonic welding of Al/Al were formed at pressure 0.25 MPa, welding time 0.25 sec, amplitude 90%. Pressure 0.25 MPa, welding time 0.4 sec, amplitude 80% are optimized for Al/Cu ultrasonic metal welding and solid-state diffusion generated by ultrasonic vibration and frictional heat is confirmed at the welded interface. (Received April 7, 2011)

Influence of filler material composition on residual stress distribution of dissimilar gas tungsten arc weldments of ultrahigh strength steels

The influence of filler material composition on the residual stress distribution in similar and dissimilar gas tungsten arc weldments of maraging steel and medium alloy medium carbon steel has been investigated. In the fusion zone, residual stresses are compressive in similar metal welds of maraging steel and tensile in similar metal welds of medium alloy medium carbon steel. In the dissimilar metal welds, the nature of residual stresses in the weld varied from compressive in maraging steel to tensile in medium alloy medium carbon steel. The magnitude of residual stresses decreased when the maraging steel is taken in soft condition in the dissimilar metal welds. Post-weld aging resulted in lowering of residual stresses in medium alloy medium carbon steel.

Microstructure, hardness and residual stress distribution of dissimilar metal electron beam welds: maraging steel and high strength low alloy steel

The present investigation reports on a study that has been taken up to develop an understanding of the electron beam welding characteristics of similar and dissimilar combination of maraging steel and high strength low alloy steel, which are in the hardened condition, i.e. maraging steel, in a solution that was in treated and aged condition, whereas high strength low alloy steel in a quenched and tempered condition before welding. The joint characterisation studies include microstructural examination, microhardness survey across the weldment and measurement of residual stresses. Maraging steel weld metal is under compressive stress rather than tensile stress as observed in low alloy steel welds because the martensite transformation occurs at a relatively low temperature. It has been observed that, in dissimilar metal welds, tensile stress is observed at the fusion boundary of low alloy steel and weld metal, whereas compressive stress is obtained at the location between weld and maraging steel fusion boundary. Dissimilar weldment contains a soft region beside the interface on maraging steel side because of the diffusion of manganese from low alloy steel towards maraging steel. The observed residual stresses, hardness distribution across the similar and dissimilar metal welds are correlated with the observed microstructures.