Investigation of Welded Joints Made of Construction Steel by the Barkhausen Noise Method

2020 ◽  
Vol 992 ◽  
pp. 957-963
Author(s):  
E. Nikolaeva ◽  
A. Nikolaev
Keyword(s):  
Stress State ◽  
Residual Stresses ◽  
Welded Joints ◽  
Arc Welding ◽  
Barkhausen Noise ◽  
Low Carbon ◽  
Butt Weld ◽  
Welded Structures ◽  
The Relationship ◽  
Weld Seams

Steel weld seams are characterized by heterogeneity of their microstructure. Microstructure affects the nature of the distribution, sign and magnitude of residual stresses. In combination with unfavorable factors (low temperature, metal hypoductility and an unsuccessful joint form) residual stresses lead to a decrease of load carrying capacity of a whole structure. In a weld seam residual stresses are distributed in a complex way and can affect the build quality of heavy section welded structures. Monitoring of residual stresses remains a big problem. Residual stresses in welds are often evaluated only by modeling. Unfortunately, all mathematical models describe the stress state of the welded material with low accuracy. Simple quality control, the results of which can be easy interpreted, is necessary. Welded joints made by manual arc welding and by automatic submerged arc welding were investigated. Butt seams of steel sheets of different thickness have been welded. Steel was low-carbon and low-alloyed. It is often used in welded structures for various purposes, including construction, and for pipelines manufacture. The temperature range of welded structures operation is very large – from-70 to 450С. The authors studied the structure of butt weld seams by the Barkhausen noise method, which is interesting as it represents an alternative to the known methods, which characterizes the structure and stress state of material. The relationship between the weld microstructure and magnetic noise is shown. Studies have allowed us to establish the relationship between the structure and magnetic properties and to evaluate the feasibility of applying the Barkhausen noise method to welded structures.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Fatigue Behavior of Butt Weld Seams: Experimental Investigation and Numerical Simulation

2014 ◽  
Author(s):  
Kay Langschwager ◽  
Alexander Bosch ◽  
Eliane Lang ◽  
Jürgen Rudolph ◽  
Michael Vormwald ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Fatigue Behavior ◽  
Special Focus ◽  
Fatigue Lifetime ◽  
Ongoing Research ◽  
Butt Weld ◽  
Welded Structures ◽  
Factors Of Influence ◽  
Weld Seams

Austenitic stainless steel of type X6CrNiNb18-10 (1.4550) is a widely used material in piping and components of nuclear power plants. The fatigue behavior of these components is often operationally determined by thermomechanical strains and corresponding stresses. Welded structures lead to complex stresses in the component and potential fatigue lifetime reductions. Various geometrical and microstructural inhomogeneities in welded structures represent the main factors of influence. Nevertheless, clear identification and quantification of various factors of influence are issues still to be resolved. Within the framework of an ongoing research project, the experimental investigation comprises uniaxial and biaxial fatigue experiments on welded joints which cover temperatures from 25°C to 350°C. Furthermore, a key issue deals with the thermomechanical fatigue behavior of machined and unmachined butt weld seams. A special focus is set on typical low cycle fatigue (LCF) tests in order to explain the behavior of the base material and the weld material to identify the influence of microstructural inhomogeneities. In addition, specimens manufactured directly from the pipe components are tested to examine the influence of the butt weld seam geometry. For a better understanding of the local strain effects, optical strain field measurements (OSFM) are conducted and used to validate numerical simulation. The finite element method (FEM) is utilized to expand the parameter space and identify the main parameters. Experimental and numerical results show that fatigue failure occurs either in the base metal in the vicinity of the welded zone or in the top layer of the weld, depending on the loading conditions. This knowledge is used to develop an approach to fatigue lifetime estimation.

FEATURES OF REPAIR OF WELDED STRUCTURES OF LARGE THICKNESSES FROM TITANIUM ALLOY VT6ch.

2021 ◽  
pp. 34-43
Author(s):  
A.V. Sviridov ◽  
◽  
М.S. Gribkov ◽  
Keyword(s):  
Titanium Alloy ◽  
Residual Stresses ◽  
Elemental Composition ◽  
Welded Joints ◽  
Mechanical Characteristics ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Vacuum Annealing ◽  
Base Material ◽  
Welded Structures

The technology of electron-beam welding (EBW) of structures of large thickness made of titanium alloy Ti–6Al–4V has been developed. A complex of metallographic studies of welded samples has been carried out. Tests to determine the mechanical characteristics of repair welded joints, that these joints made by EBW are equal in strength to the base material. The analysis of the level of residual stresses in various parts of the welded joint after repeated repair passes has been carried out. It was found that the subsequent vacuum annealing reduces the level of residual stresses in welded joints to 50 %. The analysis of the elemental composition showed that the elemental composition of the samples from the center of the weld to the base metal practically does not change for welding with the number of repeated passes up to 3.

Development of Technology for Welding Repair of Steel Housings Using a Combination of Ultrasonic Vibrations and Forced Cooling

2020 ◽  
Vol 989 ◽  
pp. 747-752
Author(s):  
Marat R. Fatkullin ◽  
Ayrat M. Fayrushin ◽  
Rif G. Rizvanov
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Pool ◽  
Welded Joints ◽  
Arc Welding ◽  
Oil And Gas ◽  
Welding Process ◽  
Subsequent Heat Treatment ◽  
Manual Arc Welding ◽  
Forced Cooling

Now, one of the most pressing issues in the development of petroleum engineering is increasing the efficiency of apparatus and machines, as well as reducing material, energy and labor resources. During operation, oil-refining equipment over time destroyed by welded joints due to the impact of power and temperature loads, corrosion, and other factors. The cause of damage in welded joints of oil and gas equipment can be justified by the occurrence in them of structural heterogeneity and residual stresses during and after welding. Today manual arc welding is almost the only applicable in the repair of equipment for oil and gas processing, which require welding operations. The high temperature source of energy and the difference in deformation properties of parts are the cause of the occurrence of substantial residual stresses, which cause a change in shape, a significant decrease in strength, a decrease in the corrosion resistance of the metal, which adversely affects the durability and reliability of the structure. At present, the technology of repair with due to manual arc welding with the concomitant heating of the defective area and subsequent heat treatment is used. A complex of simultaneously proceeding processes accompanies the welding process: thermal effects on the metal in the heat-affected zone, metallurgical processes in the weld pool and crystallization of the metal in the weld pool. The repair technology presented by us, which consists in a combination of ultrasonic shock vibrations and forced cooling during the welding process, allows to improve the mechanical properties of the welded joint, as well as to refuse to carry out heating during welding and subsequent heat treatment.

Study on the Microstructure and Mechanical Properties of 15CrMoR

2012 ◽  
Vol 472-475 ◽  
pp. 2731-2735
Author(s):  
Xiao Dong Hu ◽  
Qing Kun He ◽  
Jian Tao Lv ◽  
Yong Zhang
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Butt Weld ◽  
Heat Treated ◽  
Electric Arc Welding ◽  
The Relationship ◽  
Submerged Arc ◽  
Better Than

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.

scholarly journals Shielded Metal Arc and Thermite Welding Effect to Residual Stress, Hardness and Crack of R54-Rail Weld Joint

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Yurianto ◽  
Gunawan Dwi Haryadi ◽  
Sri Nugroho ◽  
Sulardjaka ◽  
Susilo Adi Widayanto
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Welding Process ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Crack Susceptibility

The heating and cooling at the end of the welding process can cause residual stresses that are permanent and remain in the welded joint. This study aims to evaluate the magnitude and direction of residual stresses on the base metal and heat-affected zone of rail joints welded by the manual shielded metal arc and thermite welding. This research supports the feasibility of welding for rail. The material used in this study is the R-54 rail type, and the procedure used two rail samples of one meter long each, welded using manual shielded metal arc welding and thermite welding. The base metal and heat-affected zone of the welded joints were scanned with neutron ray diffraction. The scan produces a spectrum pattern and reveals the direction of the residual stress along with it. We found the strain value contained in both types of welded joints by looking at the microstrain values, which we obtained using the Bragg equation. The results show that the magnitude and direction of the residual stress produced by manual shielded metal arc welding and thermite welding are not the same. Thermite welding produces lower residual stress (lower crack susceptibility) than manual shielded metal arc welding. The melt's freezing starts from the edge to the center of the weld to create random residual stresses. The residual stress results of both the manual shielded metal arc welding and thermite welding are still below the yield strength of the base metal.

Distribution of residual stresses in welded joints in 09G2S steel produced by adaptive pulsed-arc welding

2014 ◽  
Vol 29 (2) ◽  
pp. 131-134 ◽  
Author(s):  
Yu.N. Sarayev ◽  
V.P. Bezborodov ◽  
A.A. Grigoryeva ◽  
N.I. Golikov ◽  
V.V. Dmitriev ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Welded Joints ◽  
Arc Welding ◽  
Pulsed Arc Welding ◽  
09G2s Steel ◽  
Pulsed Arc

scholarly journals Attenuation of Barkhausen Noise Emission due to Variable Coating Thickness

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 263
Author(s):  
Katarína Zgútová ◽  
Martin Pitoňák
Keyword(s):  
Corrosion Resistance ◽  
Stress State ◽  
Magnetic Fields ◽  
Tensile Stress ◽  
Coating Thickness ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
The Real ◽  
And Shifts ◽  
The Relationship

Monitoring of the stress state of bridges by the use of the Barkhausen noise technique has been already introduced and this method can be adapted for monitoring of component’s overstressing. Measurement of Barkhausen noise on real bridges is carried out through the coating applied as a layer to increase the corrosion resistance of bodies. However, it was found that the thickness of the coating could vary, which in turn affects the Barkhausen noise signals and makes it difficult to assess the real stress state. For this reason, this paper deals with attenuation of Barkhausen noise emission due to variable thicknesses of coatings on the steel S460MC. It was found that increasing the thickness progressively decreases the Barkhausen noise emission and shifts the Barkhausen noise envelopes to the higher magnetic fields. Furthermore, the thickness of the coating also affects the relationship between the tensile stress and the Barkhausen noise.

scholarly journals EFFECT OF WELDING PROCESS PARAMETERS ON TENSILE OF LOW CARBON STEEL 283 G.C

2022 ◽  
Vol 26 (1) ◽  
pp. 79-86
Author(s):  
Hussain Hayyal ◽  
◽  
Nadhim M. Faleh ◽  
Keyword(s):  
Carbon Steel ◽  
Tensile Stress ◽  
Welded Joints ◽  
Arc Welding ◽  
Low Carbon Steel ◽  
Base Material ◽  
Welding Process ◽  
Welding Current ◽  
Low Carbon ◽  
Tungsten Electrode

In this study, three welding methods are used. The purpose to investigation the effects of SMAW, SAW, and gas tungsten arc welding (GTAW) on the tensile stress of low carbon steel conforming to ASTM 283 c. 8mm thick plates are used as base material for butt welded joints. The tensile properties of the welded joints were evaluated and the results were compared by experts using the Taguchi method to design three levels of each parameter (current, voltage and displacement speed). From this research, it is found that compared to metal shielded arc welding and submerged arc welding, the pulling effect of the gas shielded welding joint of the tungsten electrode is the best. This is mainly due to the presence of The results of using analysis of variance (ANOVA) to estimate important parameters show that welding current and speed of the weld have a significant effect on tensile stress .the experimental results are in agreement with predicted results, and the maximum error is 3%..

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