scholarly journals Influence of longitudinal control magnetic field on efficiency of the arc process

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Khaled Elsayed ◽  
Aleksandr Razmyshlyaev ◽  
Marina Ahieieva ◽  
Oleksandr Bilyk
Keyword(s):  
Magnetic Field ◽  
Base Metal ◽  
Metal Structure ◽  
Depth Of Penetration ◽  
Service Characteristics ◽  
Weld Structure ◽  
Cored Wires ◽  
Electrode Metal ◽  
Submerged Arc ◽  
Strength And Ductility

Problematic. When surfacing and welding with the action of a longitudinal magnetic field (LMF), the productivity of melting of the electrode metal increases, it is possible to control the geometric dimensions of the cross-section of the surfaced beads and welds, the structure of the surfaced metal and welds is refined, the hardness increases, the strength and ductility of the weld metal increases, and the resistance of the welds hot cracking. Research objective. Analyze the literature data on the effect of LMF on the efficiency of the arc surfacing process of worn-out surfaces of parts and structures, taking into account the magnetic properties of electrode wires and base metal to increase the efficiency of this process. Realization technique. Experiments were performed on submerged-arc surfacing with Sv-08A wire with a diameter of 5 mm with the action of an alternating LMF. Investigated the effect of the LMF frequency on the depth of penetration of the base metal and the width of the surfaced beads. The results of research. It has been established that at frequencies of the LMF within the range f = 5...50 Hz, the penetration depth is less, and the width of the bead is greater than in surfacing without the action of the LMF. In the future, it is necessary to carry out studies on the effect of LMF during surfacing with flux-cored wires and strips on the metal structure of the surfaced beads and their service characteristics. Conclusions. It has been established that for grinding the structural components of the metal surfaced with the action of LMF, it is necessary to ensure effective mixing of the liquid metal in the weld pool, that is, along its entire length. In this case, it is necessary to ensure the optimal parameters of the control magnetic fields. There is no theory that would explain the mechanism of refinement of the weld structure during arc surfacing with the action of LMF, and the existing views on this mechanism are contradictory. The data presented in the literature refer to the process of arc surfacing and welding with solid wire, there are no data on surfacing using flux-cored wires and strip electrodes.

TMF Influence on Weld Structure at the Welding of 12X18H9T

2018 ◽  
Vol 927 ◽  
pp. 1-5 ◽  
Author(s):  
Alexander D. Razmyshlyaev ◽  
Marina V. Ahieieva ◽  
Elena V. Lavrova
Keyword(s):  
Magnetic Field ◽  
Weld Metal ◽  
Arc Welding ◽  
Welding Process ◽  
Metal Structure ◽  
Transverse Magnetic ◽  
Submerged Arc Welding ◽  
Structural Components ◽  
Weld Structure ◽  
Submerged Arc

The transverse magnetic field (TMF) use allows to obtain follow effects: increasing the electrode melting coefficient, reducing the base metal penetration depth and grinding the weld metal structural components. The paper analyzed the existing literature data about the TMF influence on the refinement of the weld metal structure. It is experimentally shown that the alternating TMF influence of 6 Hz frequency reduces the grain size of weld metal is almost twice in comparison with the welding process without the TMF influence at submerged arc welding of plates of austenitic steel type 12X18H9T (X10CrNiTi18-9). The average grains size is 7-6 index, when welding without the TMF influence and the average grains size of the weld metal corresponds to 8 index, with separate inclusions of grains with 7 index when welding with the TMF influence. This is should increase the yield strength value of the weld metal in accordance with the data of Hall – Petch.

scholarly journals OPTIMAL PARAMETERS OF A LONGITUDINAL MAGNETIC FIELD PROVIDING MIXING OF THE MELT IN A BATH IN ARC SURFACING

2019 ◽  
pp. 7-15
Author(s):  
Aleksandr Razmyshlyaev ◽  
◽  
Marina Ahieieva ◽  
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Longitudinal Magnetic Field ◽  
Extreme Points ◽  
Entire Length ◽  
Process Efficiency ◽  
Optimal Parameters ◽  
Structural Components ◽  
Service Characteristics ◽  
Submerged Arc

Urgency of the research. One of the ways to improve the submerged arc surfacing process efficiency with wire is to use a control longitudinal magnetic field. (LMF). It is possible to control the geometrical dimensions of the surfaced beads, the electrode wire melting productivity increases, grinding of the structural components of the weld metal is achieved. Target setting. For effective mixing of the melt in the bath in arc surfacing with the act of the LMF, it is necessary for the melt to reach the extreme points of the tail end of the weld bath. It is necessary to determine the velocity of flows induced in the melt under the action of LMF for different frequencies and induction LMF. Actual scientific researches and issues analysis. It has been shown in recent publications that for grinding the structural components of the surfaced metal and increasing its service characteristics during arc surfacing with the act of alternating LMF, it is necessary to ensure the mixing of the melt in the bath along its entire length. Uninvestigated parts of general matters defining. The works that would deal with the mixing of the melt in the bath along its entire length during arc surfacing with the act of the alternating LMF are practically absent. The research objective. Determination of the optimal parameters of the alternating LMF, which would ensure effective mixing of the metal in the bath at submerged arc surfacing (welding) with wire. The statement of basic materials. It was assumed in the calculation method that through the head of the bath (before the arc) 90% of the total surfacing current. The dimensions of the recess (crater) under the arc in the liquid metal are determined with the help of refractory inserts. The values of velocity and acceleration, which reaches the liquid metal under the action of alternating LMF are determined. Conclusions. The optimal values of induction and frequency of LMF, providing effective mixing of the melt in the bath at submerged arc surfacing are determined.

Refinement of metal structure in arc surfacing under the effect of longitudinal magnetic field

2019 ◽  
Vol 2019 (2) ◽  
pp. 19-21
Author(s):  
A.D. Razmyshlyaev ◽  
◽  
M.V. Ageeva ◽  
E.V. Lavrova ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Longitudinal Magnetic Field ◽  
Metal Structure

Overlay Welding on Titanium and 304 Stainless Steel Using ERNiCu-7 Filler Metal by GTAW Process

2017 ◽  
Vol 728 ◽  
pp. 60-65
Author(s):  
Thanaporn Thonondaeng ◽  
Ghit Laungsopapun ◽  
Kittichai Fakpan ◽  
Krittee Eidhed
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Filler Metal ◽  
Welding Current ◽  
304 Stainless Steel ◽  
Depth Of Penetration ◽  
Bead Width ◽  
Gtaw Process ◽  
Overlay Welding ◽  
Cp Ti

Single pass overlay welding of the ERNiCu-7 filler metal on the commercial pure titanium grade 2 and the 304 stainless steel using the gas tungsten arc welding (GTAW) process was studied. The ERNiCu-7 filler metal was overlay welded on the base metals with varying welding currents; it was 30A, 40A and 50A for the CP-Ti base metal and 50A, 60A and 70A for the 304SS base metal. The experimental results showed that the overlay CP-Ti welded-specimen, increasing of welding current increased bead width and decreased depth of penetration of weldment. While for the 304SS welded-specimen, increasing of welding current increased both bead width and depth of penetration. Suitable heat inputs to achieve good geometry of weldment for overlay welding were 348J/mm for CP-Ti welded-specimen and 558J/mm for 304SS welded-specimen.

Apply the Acoustoelastic Method to Determine Residual Stresses in Welded Joints

NDT World ◽  
2020 ◽  
pp. 10-17
Author(s):  
Arkady Kamyshev ◽  
Aleksandr Danilov ◽  
Lev Pasmanik ◽  
Aleksandr Getman ◽  
Dmitry Kuzmin ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Weld Metal ◽  
Base Metal ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Stress Measurement ◽  
Metal Structure ◽  
Mechanical Tests ◽  
Residual Welding

The problem of maximum stresses estimation in the weld metal, where the direct measurements are not possible due to the influence of the metal structure on the measurement error, was solved. The influence of features of welding joints manufacturing technology on the structure of the weld metal was also determined. We use several reference welded joints of pipelines at nuclear power plants in our studies. Instrumental estimation of acoustoelasticity parameters in the weld metal in welded joints and in adjacent areas of the base metal was used together with computational modeling of the residual welding stresses distributions. Results obtained demonstrate that the error of stress measurement in the metal in the joint, which is related to the structure of the weld metal, is comparable to the material yield strength. Due to that a direct measurement of the maximum values of welding stresses is not possible. Comparison of results of acoustoelasticity parameters measurements with results of the metal macrostructure studies and mechanical tests allowed us to determine the relationship between peculiarities of structure of the weld metal sections at vertical joints with their tendency to brittle destruction. We propose and justify the NDT method of residual welding stresses in the weld metal. It is based on the principle of residual stresses balancing and employs the results of stress measurements in the base metal by acoustoelasticity. Applicability of non-destructive testing of acoustoelasticity parameters to identify the areas of welded joints with a higher tendency to brittle fracture is also justified.

A new regional/residual separation for magnetic data sets using susceptibility from frequency-domain electromagnetic data

Geophysics ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. B351-B359 ◽  
Author(s):  
Peter Tschirhart ◽  
Bill Morris ◽  
Greg Hodges
Keyword(s):  
Magnetic Field ◽  
Frequency Domain ◽  
Forward Modeling ◽  
Anthropogenic Sources ◽  
Magnetic Data ◽  
Magnetic Intensity ◽  
Depth Of Penetration ◽  
Near Surface ◽  
Long Wavelength ◽  
Magnetic Remanence

Regional-residual separation is a fundamental processing step required before interpreting any magnetic anomaly data. Numerous methods have been devised to separate deep-seated long-wavelength (regional) anomalies from the near-surface high-frequency (residual) content. Such methods range in complexity from simple wavelength filtering to full 3D inversions, but most procedures rely on the assumption that all long-wavelength anomalies are associated with deep source bodies: an incorrect assumption in some geologic environments. We evaluated a new method for determining the contributions of near-surface magnetic sources using frequency-domain helicopter-borne electromagnetic (HFEM) data. We inverted the in-phase and quadrature components of the HFEM data to produce an estimate of the spatial variation of magnetic susceptibility. Using this susceptibility information along with known topography and original survey flight path data, we calculated a magnetic intensity grid by forward modeling. There are two immediate benefits to this approach. First, HFEM systems have a limited effective depth of penetration, within the first hundred meters from the surface, so any magnetic sources detected by this method must be located in the near surface. Second, the HFEM-derived susceptibility is completely independent of magnetic remanence. In contrast, apparent susceptibility computed from the original magnetic intensity data incorporates all magnetic signal sources in its derivation. Crossplotting of [Formula: see text] versus [Formula: see text] served to reveal areas where the observed magnetic field was dominated by magnetic remanence and provided an estimate of the polarity of the remanence contribution. We evaluated an example, and discussed the limitations of this method using data from an area in the Bathurst Mining Camp, New Brunswick. Though it is broadly successful, caution is needed when using this method because near-surface conductive bodies and anthropogenic sources can cause erroneous HFEM susceptibility values, which in turn produce invalid magnetic field estimates in the forward modeling exercise.

Safety of Mega Container Ship Focusing on Brittle Crack Initiation and Arrest Behavior of Heavy Thickness Plate

2008 ◽  
Author(s):  
Masanobu Toyoda ◽  
Noboru Kiji ◽  
Yoshiyuki Nakajima ◽  
Tetsuo Okada ◽  
Yasumasa Nakanishi ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Crack Initiation ◽  
Yield Strength ◽  
Base Metal ◽  
Steel Plate ◽  
Brittle Crack ◽  
Hull Structure ◽  
Structural Details ◽  
Weld Structure ◽  
Welding Joints

The enlargement of containership requires the higher tensile strength steel and thicker plate around the hatch coaming more than the prescribed classification rules. These call the concerns about the safety of brittle crack initiation and arrestability of hull structure. It is known that increasing of stress and thickness of plates will reduce the toughness of base metal and welding joints. Therefore, the authors conducted to assure the toughness of base metal and welding joint for new higher tensile strength steel of 460MPa yield strength (YP460) and 60mm thickness. It has been considered that weld assembled steel plate structure has some arrestability at intersections of plates, though there are no prescription on the rules. And it was reported that very thicker mother plate has not enough toughness to arrest brittle crack recently. The authors investigated the structural arrestability by model testing and FE analysis and established it. Furthermore, structural details for intersections were also established. Both preventing the brittle crack initiation and arresting the brittle crack of weld structure were described, focusing on developing higher yield strength and heavier thickness of YP460 for containership in this paper.

Experimental Study on Mechanical Properties and Microstructure of 2.25Cr1Mo0.25V Steel by the Influence of Heat Treatment and Welding

2018 ◽  
Author(s):  
Qing Li ◽  
Guangxu Cheng ◽  
Mu Qin ◽  
Zaoxiao Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Base Metal ◽  
Arc Welding ◽  
Treatment Time ◽  
Welding Process ◽  
Heat Treatment Time ◽  
Evolution Of Microstructure ◽  
Welding Metal ◽  
Submerged Arc

In this paper, the mechanical properties and microstructural changes of 2.25Cr1Mo0.25V steel under different heat treatment and welding process were investigated. The heat treatment of steel during practical processing is taken as a reference. Different heat treatment time are used to obtain samples with different condition. Automatic submerged arc welding was used to obtain welding sample. The mechanical properties of different samples are obtained by tensile test; the evolution of microstructure and precipitates of different sample with heat treatment and welding was studied on scanning electron microscopy. The experimental results show that with the increase of heat treatment time, the strength of the samples decreases and the plasticity remains nearly constant. Heat treatment also affects the precipitation of carbides; the longer the heat treatment time is, the more precipitates are. Compared with the base metal, the welding metal sample has higher strength. The amount of precipitates in welding metal is much larger than it in base metal. The research on precipitation shows that there are different kinds of precipitates which have different morphologies in welding metal.

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