Spiral Weld Research Articles

Pengaruh Perbedaan Ayunan Pengelasan Dengan Metode SMAW Terhadap Kekuatan Tarik Pada Baja ST 37 Strip 5 MM

The purpose of this study was to see the effect of differences in welding swing on the tensile strength of 5 mm strip iron. The number of research samples was 6 pieces divided into two groups, the first group of 3 pieces welded with zig-zag welding swing, the second group of 3 pieces welded with spiral welding swing. The tensile test object used a tensile testing machine to determine the tensile stress value of the welding swing of each test object by slowly applying a load or force until the test object broke. This research method uses quantitative with a comparative experimental approach. The results of the welding tensile stress test of each test object sample welded with zig-zag and spiral welding swing joints showed that there was a similarity in the tensile test data, namely normal distribution, and similarity in variance. Hypothesis testing was obtained from the results of the tensile stress test of SMAW welding results with zig-zag and spiral welding swings showing a Tcount value of -8.021 (dk) = n1 + n2-2 at a significance level of 0.01 or 1%, a Ttable of 4.604 was obtained. So that the magnitude of the tensile stress of SMAW welding results with zig-zag and spiral welding swings has no significant influence.

Look into The Spiral

Beverlin Specialty Tube takes an in-depth look at the manufacturing process, benefits, and limitations of spiral weld tubes

Optimization of laser spiral welding using Response surface methodology and genetic algorithms

In the laser spiral welding (LSW) process, the welding parameters have a significant impact on the weld quality. In this paper, experiments were conducted and experimental data were collected on galvanized steel sheets using the LSW process, and mathematical models were developed using response surface methodology (RSM) and genetic algorithm (GA) to verify the specific effects of each process parameter on the weld and to perform process optimization. Laser power, welding speed, gap and focal length were selected as the influencing factors, and melt depth, melt width and concave as the output results. In the RSM model we found that the laser power was positively correlated with the weld depth and width, while the welding speed was inversely correlated with the weld depth and width, the gap was positively correlated with the amount of concave, and the focal length had no significant effect on the weld. In the GA model we use a large amount of experimental data for BP neural network training and iterative optimization using a genetic algorithm. Validation experiments were conducted on two models, and the results indicated that the two models had higher accuracy in predicting the welding depth and width compared to predicting the concave. The GA model had an 8% increase in tensile strength and a 25% increase in plasticity of the weld joint obtained from the optimal process compared to the RSM model. The GA model has higher accuracy in optimizing the LSW process.

Effect of spiral welding path and laser power on weld in laser welding of aluminum tab for lithium-ion battery

Effect of spiral welding path and laser power on weld in laser welding of aluminum tab for lithium-ion battery

Extraction of pipeline defect feature based on variational mode and optimal singular value decomposition

Because the magnetic signal information of pipeline defects obtained by magnetic flux leakage detection contains interference signals, it is difficult to accurately extract the features. Therefore, a novel pipeline defect feature extraction method based on VMD-OSVD (variational modal decomposition - optimal singular value decomposition) is proposed to promote the signal to noise ratio (SNR) and reduce aliasing in the frequency domain. By using the VMD method, the sampled magnetic signal is decomposed, and the optimal variational mode is selected according to the rate of relative change (VMK) of Shannon entropy (SE) to reconstruct the signal. After that, SVD algorithm is used to filter the reconstructed signal again, in which the H-matrix is optimized with the phase-space matrix to enhance SNR and decrease the frequency domain aliasing. The results show that the method has excellent denoising ability for defect magnetic signals, and SNR is increased by 21.01%, 24.04%, 0.96%, 32.14%, and 20.91%, respectively. The improved method has the best denoising effect on transverse mechanical scratches, but a poor denoising effect on spiral welding position. In the frequency domain, the characteristics of different defects are varied, and their corresponding frequency responses are spiral weld corrosion > transverse mechanical cracking > girth weld > deep hole > normal pipe. The high-frequency band is the spiral weld corrosion with f1 = 153.37 Hz. The low-frequency band is normal with f2 = 1 Hz. In general, the VMD-OSVD method is able to improve the SNR of the signal and characterize different pipe defects. And it has a certain guiding significance to the application of pipeline inspection in the field of safety in the future.

Crack initiation and propagation of defects adjacent to the X65 pipeline spiral weld under axial tensile force

The pipeline structure is prone to fracture by the synergistic effect of external forces and defects, which may lead to disastrous consequences. Therefore, it is of great engineering significance to study the crack initiation and propagation of defected pipelines. In this study, a series of simulations and experiments based on the wide plate tensile test were carried out. The effects of the size and position parameters of the defects adjacent to the pipeline spiral weld on crack initiation and propagation were investigated. The simulation results show that the dimensions of a single defect affected the crack initiation and propagation. Besides, the experiment results show that the mutual influence on the crack initiation and propagation between two defects was related to the position and distance of the double-defect. Observations of the pipeline stress and strain revealed that compared with the centrosymmetric double-defect, the likelihood of the fracture of the pipeline with the axisymmetric double-defect increased when the distance between the two defects was the same.

Effect of Swing-Spiral-Trajectory on pulsed fiber laser welding stainless steel/Copper dissimilar metals

The dissimilar metal combinations of SUS303 stainless steel and C19210 pure copper with a thickness of 0.2 mm by utilizing a nanosecond pulsed fiber laser was performed in lap welding with swing-spiral-trajectory. The weld effect was evaluated by means of microstructural and mechanical examinations. The influence of pulse frequency, speed and swing frequency as well as pulse waveform on mechanical properties and microstructure was clarified. The metallurgical behavior and weld penetration inside the fusion zone were observed with microscopic inspection of the welded joints and the welded surface. Part of molten pool materials inserted into copper plate formed an intertwined nails for enhancing the interfacial bonding strength was observed in the cross-section of the weldment. Additionally, the presence of a thin intertwined transition layer with solid solutions accomplished by the copper and liquid stainless steel mutual diffusion at the fusion line, indicated that the swing spiral welding pattern can strengthen the interface fusion. Some defects, such as porosities and microcracks, were also found in the welded joints. They were mainly due to the significantly different linear expansion coefficients of copper and steel. Energy dispersive spectroscopy (EDS) analysis confirmed that the interdiffusion and dissolution of copper and stainless steel occurred inside the molten pool, and the surface composition of the weld pool was dominated by iron. The microhardness (MH) study showed that the heat-affected zone (HAZ) was harder than the fusion zone on the stainless steel side, and the fusion interface microhardness much variation indicated microstructural change alongside the weld interface. The tensile test results revealed that the fracture location was in the molten pool on the stainless steel side, the fracture was protruded and the fracture mode was intergranular brittle fracture.

Study on Microstructure and Mechanical Properties of Aluminum–Copper Dissimilar Metals Joints by Nanosecond Laser Spiral Welding

Study on Microstructure and Mechanical Properties of Aluminum–Copper Dissimilar Metals Joints by Nanosecond Laser Spiral Welding

Joint formation mechanism of different laser transmission welding paths

Abstract In this study, the rectilinear, sine, and spiral paths of polymer transmission welding were used to perform welding comparative experiments, and the influence of various parameters in the polymer transmission welding of different laser paths on the joint performance and the formation of molten pool was discussed. The spiral path exhibited the highest joint strength, that increased by more than 50% compared with conventional rectilinear welding. The molten pool formed by spiral welding had a high depth-to-width ratio. Microscope observations revealed that the glass fiber flow signs in the molten pool were obvious, the glass fiber in the molten pool was abundant, and the bubble generation rate in the molten pool was lower. In this paper, Fortran language was used to construct Gaussian body heat source movement model with different paths. Results show that the spiral welding had higher welding stability than traditional rectilinear welding, welding defects caused by the lack of heat in the previous period can be properly compensated by selecting the appropriate welding period, Therefore, good joint performance can be achieved. In addition, amplitude and period are two important process parameters of spiral welding, and their sizes have important effects on joint strength and molten pool formation

An efficient adaptive combined filtering method for pipeline bending strain based on inertial in-line inspection

Long-distance high-pressure oil and gas pipelines are threated by various external forces, such as earthquakes, landslides, and other third-party damages. These additional stresses will cause the pipeline to move and bend, which not only causes the pipeline to undergo a large bending strain, but will also causes the pipeline to fail in severe cases. In-line inspection (ILI) based on strapdown inertial navigation technology has become an effective inspection method for long-distance pipelines in recent years. However, the cups or support wheels of the ILI tool encounter the pipe wall, girth or spiral welds, and other features that lead to minor oscillations and vibration during the inspection. The attitude information computed by the inertial measurement unit (IMU) is affected by these noises, and the computation of pipeline bending strain (PBS) is inaccurate. In this paper, an efficient adaptive combined filtering method based on wavelet transform with Savitzky–Golay (S-G) is proposed, which is adaptable to the variation of attitude information for the ILI tool during a long distance and time inspection. Experiments were conducted to demonstrate the effectiveness of the optimization for PBS. The average relative deviation decreased from 38.3% to 18.3%.

Weld zone porosity elimination process of galvanized steel zero-gap lap joints in remote laser spiral welding

The remote Laser spiral welding was utilized to zero-gap lap welding of galvanized steel. The relationship between pores in the weld zone and process parameters were investigated. The combination of high keyhole velocity and small spiral spacing was found to be essential for eliminating porosity in the weld area. As the spiral pitch decreases from 0.7 mm to 0.3 mm, the porosity decreases rapidly from approximately 20% to 0%. When the spiral spacing of 0.3 mm, the porosity reaches an acceptable quality level of less than 1%. The porosity tends to decrease as the keyhole velocity increases from 3 m min−1 to 9 m min−1. At the spiral pitch of 0.3 mm and keyhole velocity of 9 m min−1, the porosity in the weld area is almost completely suppressed. The peak shear strength of the spiral weld without porosity was 8819.8 N and the peak shear strength of the spiral weld with porosity was 5104.3 N. The tensile shear performance was increased by 72.8%. The low porosity caused by the spiral laser beam improves the tensile shear strength of the oscillating weld.

Finite element modelling of concrete-filled spiral-welded stainless-steel tube columns under concentric and eccentric axial loading

This study investigated the capacity of finite element modelling (FEM) approaches to predict the experimentally obtained behaviour of concrete-filled spiral-welded stainless-steel tube (CF-SWSST) short and long columns. Using the ABAQUS software, FEM was carried out of 24 CF-SWSST column tests. Nominal outside diameter to thickness ratios, effective length to diameter ratios and load eccentricity to diameter ratios equal to 51–114.5, 4.5–12.0, and 0–0.4 had been considered for the tests that were modelled. The distinct spiral weld seam geometry of the SWSST was explicitly considered in the FEM. Widely reported and accepted FEM modelling approaches and material models were adopted for this work. The concrete damaged plasticity model was utilised for the concrete core, while the stress–strain behaviour of stainless-steel was modelled using a modified Ramberg-Osgood relationship. On average, the capacities predicted by the FEM for the CF-SWSST columns were found to be non-conservative. The non-conservativeness was higher for specimens under concentric axial loading and increased with column and section slenderness. The actual to predicted capacity ratios were much closer to 1.0 for eccentrically loaded CF-SWSST columns, with conservative capacities predicted for eccentrically loaded specimens with the smallest section slenderness. For load eccentricity to diameter ratios of 0.15 and 0.4, there was negligible difference in the prediction conservativeness. Compared to analogous concrete-filled spiral-welded mild-steel tube columns, the FEM predictions obtained for the CF-SWSST columns were notably less conservative. This suggested that separate material constitutive models may be warranted for the FEM of CF-SWSSTs compared to their mild-steel counterparts. For the modelled eccentrically loaded specimens, the FEM predicted globally flexurally deformed states which agreed with those obtained experimentally, though the local buckling patterns were not replicated. In addition, the FEM qualitatively captured the experimentally obtained bending stiffness and strain variations. A modelling sensitivity study found that the FEM results were effectively equivalent even when the SWSSTs were modelled as plain seamless tubes.

Influence of boss-backing welding to ERW pipe

Station and valve chamber design often encounter the situation of drilling hole at the main pipeline and welding boss-backing to connect the branch pipe. Boss hole location should generally be at least 100 mm away from the longitudinal weld or spiral weld. However, because the electric resistance weld (ERW) is difficult to distinguish in practice, some bosses mounting position coincide with ERW or close to. In this paper, the influence of boss-backing welding directly on the longitudinal weld to the original residual stresses of ERW pipe was studied. The microstructure of pipe body and longitudinal weld after welding was also analysis. The testing results showed that the overall residual stresses of ERW pipe were relatively small. Residual stress at the longitudinal weld region were smaller than those at the pipe body region. After the boss-backing welding, the axial residual stress at the longitudinal weld and the circumferential residual stress at the pipe body region near the intersection increased sharply to 2.5 (444 MPa) and 3.8 (433 MPa) times, respectively. The invaded width and depth to the ERW pipe after welding were about 15.167 mm and 3.376 mm. Granular bainite with necklace type M-A constituents could be observed at the invaded zone. It is suggested that small welding heat input should be adopted for boss-backing welding.

Finite element modelling of concrete-filled spiral-welded mild-steel and stainless-steel tubes in flexure

This study investigated the capability of widely-used finite element modelling (FEM) methods, to predict the flexural capacity behaviour of concrete-filled spiral-welded mild-steel and stainless-steel tubes (CF-SWMSTs and CF-SWSSTs). For this purpose, twelve CF-SWMST and CF-SWSST flexural tests each were modelled using the ABAQUS software. The main parameters that had been varied in the respective tests were the outside diameter to thickness (D/t) ratio and infill concrete strength. The nominal D/t of the modelled specimens were in the range 51–114.5, while the infill concretes were of nominal grades 20 and 50 MPa. The moment capacities predicted by the FEM were observed to be, on average, conservative for the modelled CF-SWMSTs. The predicted flexural capacities were more closely in agreement with the corresponding experimental capacities for the CF-SWSSTs. The respective average actual to predicted moment capacity ratios were 1.07 and 1.00, respectively. The experimental and predicted deformation modes were also in qualitative agreement, with local buckling also being predicted by the finite element models. Though the experimentally obtained local buckling patterns were not exactly replicated, there was, nonetheless, good qualitative agreement. This study provided evidence of the capacity of commonly used FEM approaches, relating to CFSTs, to act as a predictive tool for CF-SWMSTs and CF-SWSSTs in flexure. Given the distinct difference in capacity prediction conservativeness, the study also indicated that separate material model formulations may be warranted for CF-SWSSTs compared to CF-SWMSTs. The predicted results were also found to be negligibly sensitive to explicitly modelling the spiral weld seam geometry, even though it was the default case adopted for the FEM in this study.

Finite element modelling of concrete-filled spiral-welded mild-steel tube short and long columns

The capability of finite element modelling (FEM) to predict the experimentally observed behaviour of concrete-filled spiral-welded mild-steel tube (CF-SWMST) columns was assessed in this study. FEM was carried out of 24 previously reported CF-SWMST short and long column tests using the ABAQUS software. The tube length to outside diameter ratio (L/D) of the short and long columns were 3.0–3.3 and 9.0–10.0 respectively while the nominal outside diameter to thickness ratios (D/t) of the specimens were in the range 51–114.5. Load eccentricities of 0, 0.15D, and 0.4D had been considered for the specimens in the respective tests. Widely used and well-established modelling procedures, previously reported for concrete-filled steel tube (CFST) columns, were adopted for the analyses. The concrete damaged plasticity model in ABAQUS was used as the constitutive model for concrete. The specimen geometries were represented using solid hexahedral elements, while the spiral weld seam was also explicitly modelled. With respect to the reported experimental axial capacities, the FEM provided conservative load capacity predictions for the CF-SWMST specimens with D/t ratios less than 100. The prediction conservativeness increased with increasing load eccentricity and decreasing section slenderness. For the eccentrically loaded CF-SWMST columns, the predicted globally deformed states agreed with those observed experimentally, though the local buckling patterns were not replicated in the FEM. The results indicated that the decrease in strength enhancement of the concrete core due to confinement with increasing section slenderness was possibly underestimated by the material models that were used. The FEM results were also found to be negligibly sensitive to the explicit consideration of the spiral weld seam geometry with equivalent behaviour being predicted even when the spiral welded tubes were modelled as plain tubes.

Experimental Research on Fatigue Properties of X80 Pipeline Steel for Synthetic Natural Gas Transmission

In recent years, many synthetic natural gas demonstration projects have been put into operation all over the world, and hydrogen is usually contained in synthetic natural gas. X80 is the most commonly used high-grade pipeline steel in the construction of natural gas pipelines. The compatibility between high-grade pipeline steel and hydrogen directly affects safety and reliability of long-distance pipelines. Therefore, in order to study the effect of hydrogen content on fatigue properties of high-grade pipeline steel, fatigue specimens were taken from base metal, spiral welds, and girth weld of submerged arc spiral welded pipes, respectively. Specifically, the total pressure was 12 MPa and hydrogen content was from 0 to 5vol%. Experimental results indicate that the hydrogen significantly increases the fatigue crack growth rate for both base metal, spiral weld, and heat-affected zone of X80 pipeline steel for about ten times compared with reference environment nitrogen, hydrogen would greatly reduce the fatigue life of the X80 pipeline steel, and the fatigue lifetime would decrease with the increase in hydrogen volume fraction. In order to ensure the safe operation of SNG pipeline, the hydrogen content should be controlled as low as possible.

Full Scale Dent Rebound Testing of X65 Steel Linepipe

Dents in buried pipelines can be formed due to a number of causes: third party machinery strikes, rock strikes during backfilling, pipe resting on rock, and amongst others. Dents in pipelines would not only affect short and/or long-term integrity, but would also have a potential impact on the pass capacity of in-line inspection and cleaning tools when the size of the dent is large enough. Rebound for an originally constrained dent can decrease the dent depth and improve the pass capacity of in-line inspection and cleaning tools. In order to estimate the rebound capacity of dents especially in spiral weld pipelines, a full-scale dent rebound testing program of X65 steel pipeline was designed and performed. The full scale testing was conducted on the parent material and the spiral welds. Hemispherical and pyramidal indenters were used to generate dents to different depths. Strains around the denting area during formation of the dent and changes in depths due to rebounding after removing indenter were measured. Following each rebound test, the dent profile was portrayed with a 3D laser scanner and the maximum equivalent strain was then calculated. With the information obtained from the above measurements, detailed analyses were performed and a numerical model was developed. In this paper, the approach used for the study is described first. The results and findings are then presented. The effectiveness of the developed numerical model for dent integrity management is demonstrated.

Analysis of Leakage Cause of L415M Spiral Submerged Arc Welding Pipe

The causes of longitudinal crack in gas pipeline during pressure were analyzed by means of mechanical property test, microstructure analysis, sem analysis and energy spectrum analysis. The results show that the leakage of L415M spiral submerged arc welded pipe is caused by the contact between the base material of steel pipe and low-melting copper alloy in the process of high temperature, resulting in the brittleness of liquid metal. Specifically, when the leakage site of the steel pipe is heated at an abnormal high temperature, copper penetration along the grain boundary causes embrittlement, strength reduction and crack along the grain boundary, finally leading to the crack and leak of the steel pipe.

Air void and ring gap effect on CFST arch bridges dynamic performance

Many old concrete-filled steel tube (CFST) arch bridges constructed using common concrete, the fluidity before initial setting and dry shrinkage during use create ring gaps at the interfaces of concrete core column (CCC) and spiral welding tube (SWT), and air voids in CCC. Also, unfavorable conditions of nature increase the number of gaps and voids, create more serious defects, decrease arch rib stiffness, and even change the dynamic properties of the whole bridge structure. Therefore, a finite element analysis (FEA) verified by scale-model experiments on CFST arch bridge rib members with air void and ring gap composite defects was conducted to determine the tangential stiffness of the structure. Secondly, the natural vibration and frequency of the whole bridge were analyzed using tangential stiffness and the influences of various defects on the dynamic performance of bridge was investigated. Therefore, a novel trans-scale determine system was developed for the detection of the tangential stiffness of bridges with composite defects in CFST ribs, so as to evaluate the influences of these defects on the dynamic performance of bridges. This study can provide a strong foundation for the maintenance repair of CFST arch bridges.

Microstructure Evaluation During Short Term Creep of Cr35Ni45Nb Cast Alloy Reformer Tube

In this work, a Cr35Ni45Nb alloy tube for use in a reformer furnace is subjected to high temperature (871 °C and 927 °C) creep regimes, and the microstructural changes (e.g. carbide precipitation and phase transformation) and consequent creep damage are investigated. The results of creep tests under closely similar applied stresses give different values of the Larson–Miller parameter (LMP) at different temperatures. As a result, the calculated creep rupture time at 871 °C based on the LMP value measured at 927 °C is approximately twice that which was actually measured at 871 °C. The microstructure of the as-cast tube is found to consist of an austenitic matrix with networks of MC (NbC) and eutectic (M23C6) carbides located both at grain boundaries and between dendrites. It is noted that the M23C6 carbide is not a primary eutectic carbide that can be observed in the as-cast Cr35Ni45Nb alloys. It can be argued that the primary eutectic M7C3 carbides were transformed into M23C6 due to the heat of spiral welding during the tube manufacturing process. After creep, the NbC carbides at both locations were mostly transformed to the G-phase (Nb3Ni2Si) and all the precipitates formed inside the austenitic matrix were composed of the M23C6 and G-phase. Creep cavities were initiated around the G-phase and grew cracks along the grain boundaries due to the formation of a Cr-depleted zone and the G-phase.