Manual Arc Welding Research Articles

Some studies on three body abrasive wear behaviour of hardfaced and normal plough tool material using Taguchi method

Abrasive wear is the most important influencing factor to be considered to determine life span of soil-engaging tools, especially in the case of agricultural tillage tools. A comparative study has been reported on three-body abrasive wear of normal plough tool and hardfaced plough tool materials as per ASTM G 65 standard. Hardfacing is done by manual arc welding using ZEDALLOY VB hardfacing electrode. An orthogonal array and analysis of variance are employed to investigate the optimal testing parameters. The experimental results demonstrated that the major parameter found is applied load among the other controlling factors on abrasive wear. The hardfaced plough tool material shown marked wear resistance compared to normal plough tool material.

The Microstructure and Performance Analysis of HRB400 Rebar Manual Arc Welding Joints with Rebar Materials in Civil Engineering

Manual arc welding is widely used in all kinds of welding material in the civil engineering because of their stable performance characteristics. Based on the analysis of the incision morphology, microstructure and hardness distribution of different kinds of welding joints by manual arc welding methods, how the different welding method of hot rolling ribbed rebar influenced on the performance of the organization has been emphatically discussed to further optimize its performance and provides theoretical basis for the process. The experimental results show that due to the different welding methods and the different heat input, the macro morphology of each welding joints are not identical. The microstructure of welding joints are mainly formed by proeutectoid ferrite, low carbon martensite, tempered sorbite, fine grain ferrite and pearlite. Different welding method, the vickers hardness values along the axis direction of the welded joint and along the direction of cross section are also not identical, and all these lead to the different performance of the different welding joints.

Study on the Weldability and Metallurgical Structure of 15CrMoR

The butt weld of 15CrMoR with the thickness of 55mm has been manufactured with the bonding methods of manual electric arc welding (SMAW) and submerged-arc welding (SAW), and the mechanical properties of which have been tested with the corresponding test, and the metallurgical structures have been analyzed with microscope. Conclusions have been obtained as following: the metallurgical structure of multi-layer butt weld is much more complicated than the monolayer ones; only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area; the weld zone and the fusion area will be heat treated with the next layers weld finished; the mechanical property of the multi-layer butt weld is much better than the monolayer weld.

Study on the Microstructure and Mechanical Properties of 15CrMoR

The butt weld sample with the material of 15CrMoR has been manufactured with the bonding methods of manual electric arc welding (SMAW) and submerged-arc welding (SAW). The relationship between the microstructure and the mechanical properties has been analyzed in this paper, and the conclusions have been obtained as followed: only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area for the multi-layer butt weld, the weld zone and the fusion area will be heat-treated by the next layer welding; the hardness along central intersection shows a W-shaped distribution, and the zone with normalizing organization has the lowest hardness and the surface layer has the highest hardness; the mechanical properties of the multi-layer butt weld are much better than the monolayer weld’s.

A CMOS Visual Sensing System for Welding Control and Information Acquirement in SMAW Process

Abstract A sequential research work on visual information of manual arc welding pool dynamics are presented in this paper. An optical inspection system, for monitoring the shielded manual arc welding (SMAW) process is described. The system consisted of a vision sensor that consisted of a Complementary Metal Oxide Semiconductor (CMOS) camera and lenses, image processing algorithms, and a computer controller. During welding, an image of the weld pool and its vicinity was captured when basic current of welding power. Experimental results showed that the temperature signal varies greatly in the case of instabilities of the weld pool that cause weld defects. The visual information acquirement methods are focused in computer vision sensing, image processing and characteristic extraction of the weld pool surface from the single-item pool images by particular algorithms control strategies are developed to control welding pool dynamics during SMAW.

Practical insight on scope of sliding mode control in arc welding process

Unlike most control systems, a single arc welding controller performs different welding functions using dynamics of different arc characteristics meeting complex output characteristics – that includes apart from joint characteristics are arc light intensity, fumes and particulate matters, etc. Moreover, unavailability of feedback in major loop for control of heat input to joint divides the parameters of the complete process into external and intrinsic ones. Intrinsic parameters define arc characteristics. Dynamic non-linear intrinsic parameters cannot be made insensitive even through sliding mode control. Representative dynamical systems for starting, stopping and normal welding are also different. This article explores the scope of practical implementation of SMC to complete range of arc welding process. In constant current (CC) manual arc welding process, arc is extinguished by increasing the arc length much beyond the controller can sustain. In that process, it produces large unusable heat causing discomfort to the welder and co-workers. The present article, as well, discusses implementation mechanism of SMC to optimise arc light intensity and reduce heat generation in arc column in order to convert mechanism of manual arc extinction of SMAW welder friendly. Chattering issue is not important.

Investigating the Influence of the Power Supply Type upon the Weld Joints Properties and Health Characteristics of the Manual Arc Welding

The given work considers the influence of the power supply type (diode rectifier ВД-306 and upon new generation inverter Nebula-315) upon the chemical composition, microstructure, mechanical properties of the weld joints and health characteristics of the manual arc welding process.

Weldability of AISI 430/AISI 1030 Steel Couples via the Synergic Controlled Pulsed (GMAW-P) and Manual Gas Metal Arc (GMAW) Welding Techniques

In this study, ferritic stainless steel (AISI 430)/medium-carbon steel (AISI 1030) couples, having two different properties of 10 mm thick, were welded by using the synergic controlled pulsed (GMAW-P) and manual gas metal arc welding (GMAW) techniques. Constant wire feed speed, voltage, welding speed, and gas flow rates (3.2 m/min, 22.5 V, 4 mm/s, 16 L/min) were used in these techniques. The interface appearances of the welded samples were examined by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-Ray diffraction (XRD). In order to determine mechanical properties of samples, the tensile and microhardness tests were conducted. The GMAW-P joints of AISI 430/AISI 1030 steel couples showed superior tensile strength, less grain growth, and narrower heat affected zone (HAZ) when compared with GMAW joints, and this was mainly due to lower heat input, finer fusion zone grain, and higher fusion hardness.

Finite difference simulation of low carbon steel manual ARC welding

This study discusses the evaluation and simulation of angular distortion in welding joints, and the ways of controlling and treating them, while welding plates of (low carbon steel) type (A-283-Gr-C) through using shielded metal arc welding. The value of this distortion is measured experimentally and the results are compared with the suggested finite difference method computer program. Time dependent temperature distributions are obtained using finite difference method. This distribution is used to obtain the shrinkage that causes the distortions accompanied with structural forces that act to modify these distortions. Results are compared with simple empirical models and experimental results. Different thickness of plates and welding parameters is manifested to illustrate its effect on angular distortions. Results revealed the more accurate results of finite difference method that match experimental results in comparison with empirical formulas. Welding parameters include number of passes, current, electrode type and geometry of the welding process.

Microstructure and Wearability of Surface Coating of Fe-Based Amorphous Core Welding Rod

Based on the classic formula of J507 coated electrode，the welding rods were prepared by adding Fe41Co7Cr15Mo14C15B6Y2 Fe-based amorphous alloy or HO8A as welding core. The surface coating on Q235 was made by manual electric arc welding with two kinds of welding rods,while Ar2 gas is used to cool the weld layer. The microstructure and wearability of welded joint and the coating layer were investigated by the means of metallographic analysis, SEM,XRD and M-2000 wear tester.The results show that the coating layer is in the amorphous state,and the wearability of surface coating with Fe-based amorphous core welding rod is better than another.

Effect of Solution Temperature on Microstructure of 2205 Duplex Stainless Steel Welded Joints

The various temperature solution experiments were carried out in this paper, which for 2205 duplex stainless steel joints welded by manual arc welding. The evolutions of microstructure in pre/post solution treatment and the contents of ferrite phase were conducted by using optical microscope and ferrite scope detector. The analysis results in the welded, the heat affected and the base metal regions show that suitable solution treatment is effective to adjust the welded microstructure condition. The austenite in each region transformed into ferrite when the temperature enhanced from 1050 to 1200°C. This resulted in increasing the volume of ferrite and coarsening the grain. All microstructure characteristics of the three regions were taken into account, it deduced that the feasible solution temperature range was 1050~1100°C for 2205 duplex stainless steel welded joint.

The Development of Multifunctional Inverter Power

A multifunctional inverter welding machine with the functions of DC gas tungsten arc welding, argon tungsten pulsed arc welding, manual arc welding and air plasma arc welding gather in integral whole is introduced in this work. In whose development, the theory of half-bridge series resonant inverter is used as the basis, while the fast SCR as the inverter. When in the situation of welding, full-wave rectification is used, with a working voltage of 36V; while in the situation of cutting, bridge rectifier is used, with a working voltage of 100V~125V. According to a large number of experiments and tests in the development process, the correctness of the mathematical modal of the fast SCR inverter is verified, and a new method of inverter circuit parameter design is obtained. By which, the theoretical basis is provided for the development of inverter welding machine.

Effect of manual arc welding conditions on the nature of corrosion failure of welded joints in 12Cr18Ni10Ti steel in acid media

To increase the corrosion resistance of welded joints in steels and alloys, it is necessary to obtain information on the processes taking place during the formation of the structure in the weld met...

Solidification structure in Ti–5Ta–1·8Nb weld

Solidification structure of a weld in a manual gas tungsten arc welding of 3 mm thick Ti–5Ta–1·8Nb plates has been examined using optical/scanning electron microscopy, EDX spectroscopy and electron backscattered diffraction techniques. The weld exhibited columnar grains of prior β, with a substructure of martensitic α′. The backscattered electron image revealed the solidification mode to be cellular–dendritic, and the EDX analysis confirmed the partitioning of Ta atoms between the dendrites. The crystal orientation of the product α′ obtained by electron backscattered diffraction and the Burgers orientation relationship (for β→α′ transformation) were used to predict the orientation of parent β grains in the weld zone, and the long dendritic arms were found to be aligned parallel to β<100>. Analytical solution based on Rosenthal equation was used to calculate the temperature cycle of the welding process. The solidification mode predicted from calculated G/R ratio (where G is solidification gradient and R is rate of solidification) and Kurz–Fischer map matched with the observed cellular–dendritic solidification structure.

Calculation of parameters for welding annular joints of high-strength steel Kh80 gas pipelines

Parameters are calculated for a welding regime for gas pipeline annular joints made of high-strength steel Kh80. A structural diagram for the most dangerous area, i.e., the zone near the seam (ZNS) of a welded joint, and the dependence of hardness and impact strength on the structure and phase composition of the ZNS metal, formed during welding with different cooling rates, and also standard specifications for welded annular joints of steel Kh80 pipes are provided. Parameters are calculated for a manual arc welding regime for an annular joint and the recommended regime parameters are indicated for providing the required ZNS metal cooling rate.

Microstructure and wear properties of the Fe–Ti–V–Mo–C hardfacing alloy

In this study, different hardfacing layers were produced by shield manual arc welding (SMAW) process in which a bare electrode of H08A was coated with fluxes, to which different measures of ferrotitanium (Fe–Ti), ferrovanadium (Fe–V), ferromolybdenum (Fe–Mo) and graphite had been added. The influence of added alloy elements on the microstructure and wear properties of the Fe-based hardfacing layers was investigated. The results showed that complex carbides of TiC–VC–Mo 2C were synthesized via metallurgic reaction during welding. Carbides are uniformly dispersed in the matrix. The addition of graphite and ferromolybdenum can enhance macro-hardness and wear resistance of the hardfacing layer significantly, but increase the crack sensitivity of the hardfacing layer. With the increasing of the additions of Fe–Ti and Fe–V, the macro-hardness and wear resistance of the hardfacing layers increased. A good resistance to cracking and wear resistance of the hardfacing layer could be obtained, when the amounts of graphite, Fe–Ti, Fe–V and Fe–Mo were controlled within a range of 8–10%, 12–15%, 10–12% and 2–4%, respectively. The wear resistance of the deposited layer surfaced by Fe–Ti–V–Mo–C hardfacing alloy possesses a higher wear resistance and less friction coefficient than that of the deposited layer surfaced by EDRCrMoWV-A3-15 hardfacing alloy.

Effect of molybdenum on the microstructure and wear resistance of Fe-based hardfacing coatings

Fe-based hardfacing alloys containing molybdenum compound have been deposited on AISI 1020 steel substrates by shield manual arc welding (SMAW) process. The effect of Mo on the microstructure and wear resistance of the Fe-based hardfacing alloys were investigated by means of X-ray diffraction, optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis, as well as wear test. The results indicated that cuboidal and rod-type complex carbides were synthesized in the lath martensite matrix. The fraction of carbides in hardfacing layer increased with an increasing of Mo content. The hardfacing layer with good cracking resistance and wear resistance could be obtained when the amounts of Fe–Mo was controlled within a range of 3–4 wt.%. The improvement of hardness and wear resistance of the hardfacing layers attributed to the formation of Mo 2C carbide and the solution strengthening of Mo.

Evaluation of the quality of the components of the process of manual arc welding using entropy methods

Evaluation of the quality of the components of the process of manual arc welding using entropy methods

Non-uniformity of residual stress profiles in butt-welded pipes in manual arc welding

Abstract Welding residual stresses in pipes of small diameter are especially critical when the fluid transported has high acidity. In manual welds, various factors can alter the behavior of residual stresses. The present work presents experimental results on the profile of residual stresses in manually welded butt joints. The residual stress measurements were carried out on the external surface with a mini-diffractometer X-ray. The results show that significant variations can occur in the welding residual stress behavior even under similar welding conditions.

Microstructure of the Fe-based hardfacing layers reinforced by TiC-VC-Mo 2C particles

In this study, the hardfacing alloys with different measures of ferrotitanium (Fe–Ti), ferrovanadium (Fe–V), ferromolybdenum (Fe–Mo) and graphite were deposited on AISI 1020 steel substrates by shielded manual arc welding (SMAW). Fe-based hardfacing layers reinforced by carbide particles were produced. The thermodynamic analysis for carbide and effect of the carbide forming elements on the properties of hardfacing layers were also discussed. The experimental results showed that TiC-VC-Mo 2C carbides could be synthesized by metallurgic reaction during SMAW process. Carbides with particle sizes in the range 1–3 μm are uniformly dispersed in the matrix. The hardfacing layer with good cracking resistance and high hardness could be obtained when the amounts of graphite, Fe–Ti, Fe–V and Fe–Mo were controlled within a range of 8–10%, 12–15%, 10–12% and 2–4%, respectively.