scholarly journals Underwater Local Cavity Welding of S460N Steel

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5535
Author(s):  
Jacek Tomków ◽  
Anna Janeczek ◽  
Grzegorz Rogalski ◽  
Adrian Wolski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Standard Deviation ◽  
Welded Joints ◽  
Welded Joint ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Carbon Equivalent ◽  
High Porosity ◽  
Weld Porosity

In this paper, a comparison of the mechanical properties of high-strength low-alloy S460N steel welded joints is presented. The welded joints were made by the gas metal arc welding (GMAW) process in the air environment and water, by the local cavity welding method. Welded joints were tested following the EN ISO 15614-1:2017 standard. After welding, the non-destructive—visual, penetrant, radiographic, and ultrasonic (phased array) tests were performed. In the next step, the destructive tests, as static tensile-, bending-, impact- metallographic (macroscopic and microscopic) tests, and Vickers HV10 measurements were made. The influence of weld porosity on the mechanical properties of the tested joints was also assessed. The performed tests showed that the tensile strength of the joints manufactured in water (567 MPa) could be similar to the air welded joint (570 MPa). The standard deviations from the measurements were—47 MPa in water and 33 MPa in the air. However, it was also stated that in the case of a complex state of stress, for example, bending, torsional and tensile stresses, the welding imperfections (e.g., pores) significantly decrease the properties of the welded joint. In areas characterized by porosity the tensile strength decreased to 503 MPa. Significant differences were observed for bending tests. During the bending of the underwater welded joint, a smaller bending angle broke the specimen than was the case during the air welded joint bending. Also, the toughness and hardness of joints obtained in both environments were different. The minimum toughness for specimens welded in water was 49 J (in the area characterized by high porosity) and in the air it was 125 J (with a standard deviation of 23 J). The hardness in the heat-affected zone (HAZ) for the underwater joint in the non-tempered area was above 400 HV10 (with a standard deviation of 37 HV10) and for the air joint below 300 HV10 (with a standard deviation of 17 HV10). The performed investigations showed the behavior of S460N steel, which is characterized by a high value of carbon equivalent (CeIIW) 0.464%, during local cavity welding.

Microstructures and Mechanical Properties of Welded Joints of Several High Tensile Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Plates ◽  
Fatigue Properties ◽  
High Tensile Strength ◽  
The Matrix ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.

scholarly journals Effect of Reversed Austenite on Mechanical Properties of ZG06Cr13Ni4Mo Repair Welded Joint

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yunhai Su ◽  
Zuyong Wei ◽  
Gang Li ◽  
Xiangwen Zhang ◽  
Hedi Ci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Welded Joint ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Reversed Austenite ◽  
Repair Welding ◽  
Gas Tungsten Arc

In this work, gas tungsten arc welding (GTAW) was used to repair ZG06Cr13Ni4Mo martensitic stainless steel. Repair welding occurred either once or twice. The changes in the microstructure and properties of the repair welded joints were characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscattering diffraction (EBSD), tensile and impact tests. The effects of reversed austenite in repair welded joints on microstructure and mechanical properties were studied. The results show that the microstructure of the welded joint after repair welding consists of a large amount of martensite (M) and a small amount of reversed austenite (A), and the reversed austenite is distributed at the boundary of martensite lath in fine strips. With the increase in the number of welding repairs, the content of reversed austenite in the welded joint increases. The microstructure in the repair welded joints is gradually refined, the microstructure in the once and twice repaired joints is 45.2% and 65.1% finer than that in the casting base metal, respectively. The reversed austenite presented in the repair welded joints decreases the tensile strength by 4.8% and 6.7%, increases the yield strength by 21.3% and 26.4%, and increases the elongation by 25% and 56%, respectively, compared with the casting base metal. In addition, the reversed austenite mainly nucleates and grows at the boundary of lath martensite. The refinement of the martensite structure was due to the generation of reversed austenite and the refinement of original austenite grain by the welding thermal cycle. After repair welding, the reverse austenite appeared in the repair welded joints and the tensile strength decreased slightly, but the plastic toughness was significantly improved, which was conducive to the subsequent service process.

scholarly journals Influence of Alloying Element in Filler Metal on Mechanical Properties of A6061 Al Alloy Welded Joints

2020 ◽  
Vol 9 (3) ◽  
pp. 661-666
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Welded Joint ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Al Alloy ◽  
Fine Grain ◽  
Metal Arc Welding ◽  
Arc Welding Process ◽  
Filler Metals

The current work is intended to study the influence of using ER4043 and ER5356 filler metals on mechanical properties of A6061 Al alloy welded joint made by gas metal arc welding process (GMAW). For this study, 12mm plates of these materials were joint using a type single V groove butt joints with four layers and five passes configurationof welded joints. The soundness of the quality of the weld joint was investigated by X-ray Ct-Scan technique. The joint made with the ER4043 presented an enhancement of mechanical properties. In comparisonwith the joint made with ER5356, Al A6061 with ER4043 welded joint shows to have an advantage due to the formation of very fine grain and have uniformly distributed porosity in the weld region area.

Research on Welding Process of Low Alloy High Strength Steel 20MnTiB

2019 ◽  
Vol 815 ◽  
pp. 114-119
Author(s):  
Zhen Liang Li ◽  
Hao Ke ◽  
Yang Shen ◽  
Xi Wang ◽  
Jiao Zhong
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
High Strength Steel ◽  
Welded Joint ◽  
Welding Process ◽  
High Strength ◽  
Post Heat Treatment ◽  
Line Energy ◽  
Metallographic Structure ◽  
Strength Change

In this paper, the properties of the base metal of the low-alloy high-strength steel 20MnTiB, the welding process and the microstructure and properties of the welded joints were studied. The results are as follows: post-heat treatment below 400°C, the strength change of the steel decreases slowly, the elongation does not change significantly, and the metallographic structure is not obvious. When the temperature is above 400, the strength is greatly reduced. And its plasticity increases remarkably, and precipitates on the grain boundary are precipitated and grown on the metallographic structure. When the line energy is in the range of 9.6~12.0kJ/cm, the mechanical properties and microstructure of the welded joints meet the requirements, and the welding process that meets the requirements is studied. Finally, the mechanical properties and microstructure of the welded joint are studied. Provide a reference for the research and application of steel.

Correlation between GMAW Parameters and Mechanical Properties of Hot-Rolled, High-Strength Low-Alloy (HSLA) Steel Butt Joints

2021 ◽  
Vol 890 ◽  
pp. 25-32
Author(s):  
Alin Constantin Murariu ◽  
Aurel Valentin Bîrdeanu
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Hsla Steel ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
Main Process ◽  
Hot Rolled

In all industrial fields, the product requirements are more and more demanding. HSLA steels are designed to provide higher atmospheric corrosion resistance and improved mechanical properties than structural steels. The paper presents the results of an experimental program based on factorial design, applied to predict the mechanical properties of butt-welded joints of S420MC and S460MC hot-rolled, high-strength low-alloy (HSLA) steel plates with 2mm, 4mm and 8mm thickness. Gas Metal Arc Welding (GMAW) was used and correlations between the main process parameters and the related mechanical properties of the welded joints were found. Obtained mathematical correlations can be exploited to provide optimal combination of welding parameters to fit the quality requirements of the end-users for envisaged welded product.

scholarly journals Structural Aspects of Execution and Thermal Treatment of Welded Joints of Hardox Extreme Steel

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 915 ◽  
Author(s):  
Konat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Welded Joints ◽  
Base Material ◽  
Steel Structures ◽  
High Strength ◽  
Carbon Equivalent ◽  
Material Structure ◽  
Welding Processes ◽  
Structural Aspects

The paper presents structure and mechanical properties of welded joints of the high-strength, abrasive-wear resistant steel Hardox Extreme. It was shown that, as a result of welding this steel, structures conducive to lowering its abrasion-wear resistance are created in the heat-affected zone. Width of the zone exceeds 60 mm, which results in accelerated wear in the planned applications. On the grounds of the carried-out examinations of structures and selected mechanical properties, a welding technology followed by heat treatment of heat-affected zones was suggested, leading to reconstruction of HAZ structures that is morphologically close to the base material structure. In spite of high carbon equivalent (CEV) of Hardox Extreme, the executed welding processes and heat treatment did not result in the appearance, in laboratory conditions, of welding imperfections in the welded joints.

scholarly journals The Effect of Laser Offset Welding on Microstructure and Mechanical Properties of 301L to TA2 with and without Cu Intermediate Layer

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1138 ◽  
Author(s):  
Xiaohui Zhao ◽  
Zhenfu Shi ◽  
Chao Deng ◽  
Yu Liu ◽  
Xin Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Brittle Fracture ◽  
Welded Joints ◽  
Intermediate Layer ◽  
Welded Joint ◽  
Eutectic Reaction ◽  
Dissimilar Materials ◽  
Microstructural Characterization ◽  
The Other

Based on dissimilar materials of 301L/TA2, the effect of laser offset and copper intermediate layer on welded joints was investigated. First, the process optimization of laser offsets indicated that the tensile strength of welded joint without intermediate layer was reached to the highest value when the laser was applied on the TA2 side. On the other hand, the tensile strength of welded joint with intermediate layer performed well when laser was applied in the middle position. Then, microstructural characterization and mechanical properties of welded joints were observed and tested. Based on eutectic reaction and peritectic reaction: TiFe and TiFe2 compounds were produced for welded joint without intermediate layer. Cu-Fe solid solutions and Cu-Ti compounds were generated when copper was used as the intermediate layer. The maximum tensile strength of welded joint with and without copper intermediate layer were 396 and 193 MPa, respectively. Finally, fracture mechanism of 301L/TA2 welded joint was studied: Fe-Ti compounds caused brittle fracture of welded joints without intermediate layer; brittle fracture took place in rich copper and Cu-Ti compounds area of welded joints with copper intermediate layer.

scholarly journals Effect of ultrasonic impact time on Microstructure and properties of 7A52 aluminum alloy tandem MIG welded joint

2021 ◽  
Author(s):  
Furong Chen ◽  
Yihang Yang ◽  
Nan Li
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Welded Joints ◽  
Welded Joint ◽  
Treatment Time ◽  
High Strength ◽  
Proper Treatment ◽  
Welding Condition ◽  
7A52 Aluminum Alloy

Abstract 7A52 (Al-Zn-Mg-Cu) alloy is a high-strength aluminum alloy, its welded joints are often accompanied by defects such as poor wear resistance and low fatigue strength. Herein, we try to optimize the welded joint of 7A52 aluminum alloy by using ultrasonic impact treatment (UIT). Generally, the mechanical properties such as microhardness and fatigue strength of the welded joint after UIT will be improved. 7A52 aluminum alloy tandem metal inert gas (MIG) welded joints with UIT time per unit area of 2.5 min, 5 min, 10 min, 15 min, 30 min, and 75 min were studied. Through the surface topography, microstructure observation, and mechanical properties test, the time parameters of excessive treatment, lack of treatment, and proper treatment were selected, and the effects of UIT, excessive treatment, lack of treatment, and proper treatment on fatigue strength were analyzed. Test results show that, the mechanical properties of welded joints after UIT are improved. The proper treatment time is 15min and its fatigue strength is 37.86MPa, respectively under the stress ratio of 0.1. Compared to the original welding condition with a fatigue strength of 28.61MPa, the fatigue strength of the welded joints of 7A52 aluminum alloy increased by 32.33%. The largest percentage of grain size reduction occurs when the UIT is 15 min. Moreover, excessive treatment and lack of treatment will not further refine the grains and optimize the mechanical properties.

scholarly journals The Ultimate Load Estimation of Welded Joints of High-Strength Steels subject to Mechanical and Geometric Heterogeneity

2020 ◽  
pp. 99-108
Author(s):  
S B Sapozhnikov ◽  
M A Ivanov ◽  
I A Shcherbakov
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Stress Concentrator ◽  
Ultimate Load ◽  
Welded Joint ◽  
High Strength Steels ◽  
High Strength ◽  
Welding Wire

In this paper we consider the problems arising in the numerical estimation of the ultimate load of welded joints of high-strength steels with slight hardening. The stress concentrator in the transition node from the deposited to the base metal is modeled based on the example of welding a roller wire on a plate made of high-strength steel. The use of welding wire with a yield point lower than that of the base metal allowed to simulate areas of the welded joint with heterogeneous mechanical properties. The geometry of three areas of the welded joint is studied, i.e. weld metal, heat-affected zone (HAZ) and the base metal. Mechanical properties of all three areas are determined by calculation and experimentally. For this purpose, it is proposed to consider the material in all sections as ideally elastic-plastic, and the yield strength is uniquely associated with the hardness in the indentation zone (a Rockwell diamond cone is used). Calculations of the inelastic indentation process by the finite element method (FEM) in axis-symmetric formulation allowed obtaining a linear relationship between the hardness and the yield strength with a coefficient of 0.418. Tests at a quasi-static three-point bend (with stretching in the surfacing area) were carried out on sample beams cut perpendicular to the direction of welding. The “force-deflection” diagrams are obtained and compared with the calculated curves (FEM in a three-dimensional formulation with an explicit consideration of the complex configuration of all sections and different yield stress in the areas determined by local hardness values). There is a good agreement between the calculated and experimental ultimate loads. The proposed method of the three-stage study (determination of local hardness, yield strength in the areas and the ultimate load) can be effectively used to assess the ultimate loads of the welded joints due to the low parametricity of the proposed models of materials inelastic deformation in areas for which it is impossible to manufacture standard samples for the study of mechanical properties. The experimental study of the strengthening effect of the seam with a stress concentrator in the form of an angle of 90 degrees on the value of the ultimate bending load showed that the removal of the deposited metal does not lead to an increase in the ultimate load of the welded joint when using the welding wire of low-carbon high-plastic steel.

scholarly journals Influence of Welding Speeds on the Morphology, Mechanical Properties, and Microstructure of 2205 DSS Welded Joint by K-TIG Welding

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3426
Author(s):  
Shuwan Cui ◽  
Shuwen Pang ◽  
Dangqing Pang ◽  
Zhiqing Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundary ◽  
Welding Speed ◽  
Welded Joints ◽  
Welded Joint ◽  
Tig Welding ◽  
Phase Ratio ◽  
Boundary Misorientation ◽  
Two Phase

In this paper, 8.0 mm thickness 2205 duplex stainless steel (DSS) workpieces were welded with a keyhole tungsten inert gas (K-TIG) welding system under different welding speeds. After welding, the morphologies of the welds under different welding speed conditions were compared and analyzed. The microstructure, two-phase ratio of austenite/ferrite, and grain boundary characteristics of the welded joints were studied, and the microhardness and tensile properties of the welded joints were tested. The results show that the welding speed has a significant effect on the weld morphology, the two-phase ratio, grain boundary misorientation angle (GBMA), and mechanical properties of the welded joint. When the welding speed increased from 280 mm/min to 340 mm/min, the austenite content and the two-phase ratio in the weld metal zone (WMZ) decreased. However, the ferrite content in the WMZ increased. The proportion of the Σ3 coincident site lattice grain boundary (CSLGB) decreased as the welding speed increased, which has no significant effect on the tensile strength of welded joints. The microhardness of the WMZ and the tensile strength of the welded joint gradually increased when the welding speed was 280–340 mm/min. The 2205 DSS K-TIG welded joints have good plasticity.

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