Study on Quality Control of the Laser Welding Joint

2013 ◽  
Vol 442 ◽  
pp. 276-281
Author(s):  
Qiang Wu ◽  
Lan Ying Xu
Keyword(s):  
Laser Welding ◽  
Salt Water ◽  
Harmful Effect ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Welding Parameters ◽  
Test Results ◽  
Welding Joint ◽  
Corrosion Rates

During laser welding process of high-strength galvanized steel, adopting guiding arc plate and the connecting arc plate can avoid harmful effect resulted in unstable melting width. The galvanized layer protecting joint is inevitably lost by having been burned, which affects stain resistance of welding joint. So salt water with the concentration of 3% is used in the corrosion test for the samples welded under different laser parameters, mass variation and metallographic microscopes are gained after joint being corroded. The test results indicate that the corrosion rates of the joint are different under different welding parameters during laser welding of high-strength galvanized steel; their average corrosion rates are coincident with that of base metal and laser welding technology hardly effect corrosion resistance of the joint.

Optimization for Laser Welding Fillet Joint Based on Response Surface Method

2011 ◽  
Vol 211-212 ◽  
pp. 1110-1114
Author(s):  
Xiao Yun Zhang ◽  
Yan Song Zhang
Keyword(s):  
Laser Welding ◽  
Response Surface ◽  
Weld Seam ◽  
Welding Process ◽  
Galvanized Steel ◽  
Plant Production ◽  
Welding Parameters ◽  
Technical Instructions ◽  
Fillet Joint ◽  
Laser Welding Process

The wide use of galvanized steel in automobile manufacturing brings much challenge to the roof to body-side laser welding process. Fillet joint is an effective way to solve this problem such as pore in laser welding process. However, there is little research on this type of complicated joint process. Focused on this problem, take metallographic size of weld seam as the weld quality criteria, response surface methodology (RSM) is used to study the influence of laser welding parameters on weld seam quality. Finally, the optimum welding parameters are concluded to give technical instructions for the plant production.

scholarly journals Microstructural Characterization and Mechanical Properties of Laser Beam-Welded Dissimilar Joints between A6000 Aluminum Alloy and Galvanized Steel

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 543
Author(s):  
Nkopane Angelina Ramaphoko ◽  
Samuel Skhosane ◽  
Nthabiseng Maledi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
Welding Process ◽  
Galvanized Steel ◽  
Vehicle Body ◽  
Welding Parameters ◽  
Dissimilar Joints

This paper presents the laser beam welding process of a lap joint between galvanized steel (Z225) and an aluminum alloy (A6000) from an IPG fiber laser. Welding of steel to aluminum has become popular in the automotive industry as a means of reducing the total vehicle body mass. This approach reduces fuel consumption and, ultimately, carbon emissions. Laser welding parameters used to control heat input for the study were laser power ranging between 800 and 1200 W, as well as laser welding speeds between 2 and 4 m/min. Distinct features of the dissimilar joints were microscopically examined. The SEM-EDS technique was employed to study the intermetallic phases along the Fe-Al interface. The outcome revealed the presence of “needle-like phases” and “island-shaped phases” at high heat inputs. Traces of both Fe2Al5 and FeAl3 phases were detected. For low heat input, there was evidence of insufficient fusion. Weld width was influenced by welding parameters and increased with an increase in heat input. Mechanical properties of the joints indicated that the microhardness values of the weld joints were higher than those of both base metals. The maximum tensile shear strength obtained was 1.79 kN for a sample produced at 1200 W and 3 m/min.

Mechanical properties and fatigue behavior of CO2 laser beam welded armor steel joints

2020 ◽  
Vol 62 (7) ◽  
pp. 689-697
Author(s):  
Z. Balalan ◽  
F. Sarsilmaz ◽  
O. Ekinci
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
High Strength ◽  
High Heat ◽  
Strength Properties ◽  
Welding Parameters ◽  
Test Results ◽  
Input Parameters ◽  
High Heat Input

Abstract Armor 500T steel used in armored military vehicles and marine vehicles were joined by CO2 laser beam welding method by applying three welding powers and two welding speeds under shielding argon atmosphere. From microstructure and microhardness results, under low laser welding power and high welding traveling speeds, microstructural transformation in the joining region of the performed welds occurred at a narrower distance as compared to other parameters, and it was determined that four regions formed independent of each other for each parameter group. Furthermore, it was determined that there is a gradual decrease in the microharness values of samples in which welding parameters cause heat input to decrease. The fatigue test results of all samples showed high strength properties in the parameters with high heat input. Additionally, tensile test results for all samples with high heat input parameters also exhibited high strength properties. Fracture at the intersection at high heat input parameters of a relatively ductile separation type occurred in HAZ whereas, at other parameters fracture occurred at the weld center and wide gap semi-brittle fracture behavior was observed. As a consequence, it was found that the most effective parameter as compared with laser welding power is laser welding traveling speed.

Impact of Welding Parameters on Weld Seam Properties of Seamless X80 Linepipe Steel Grade

2014 ◽  
Author(s):  
Claas Bruns ◽  
Jörg Wiebe ◽  
Dorothee Niklasch ◽  
Denise Mahn ◽  
Tanja Schmidt
Keyword(s):  
Weld Seam ◽  
Mechanical Test ◽  
Base Material ◽  
Welding Process ◽  
Charpy Impact ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Test Results ◽  
Linepipe Steel

The challenging exploration conditions appearing in ultra deep offshore projects promoted the development of high strength linepipe steel grades with yield strength of 80 ksi and higher in recent years. With increasing strength more attention has to be paid to welding procedures to realise the required mechanical properties of the weld seam. The combination of demanding toughness requirements at low temperatures and adequate corrosion resistance of welded joints is a key for complex deep offshore riser and linepipe applications. The welding process was optimised by Vallourec with respect to heat input and preheating temperature for joining seamless quenched and tempered pipes in grade X80. A root welding strategy has been developed particularly with regards to sour service applications. Extensive mechanical test results including Charpy impact testing, hardness, CTOD and SSC testing will be presented. In addition Gleeble trials were carried out using different thermal cycles to simulate multilayer welding. The aim was to improve the understanding of the base material behaviour in the heat affected zone (HAZ) during welding. The microstructure was characterized by LOM, SEM and furthermore hardness and Charpy impact tests were executed. Based on the gathered knowledge and test results welding recommendations and welding strategies for high strength steel X80 seamless line pipes are deduced.

scholarly journals The Investigation of Laser Lap Welding Process on High-Strength Galvanized Steel Sheets

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Shiquan Zhou ◽  
Yi Zhao ◽  
Zhenguo Peng ◽  
Fangjie Ren
Keyword(s):  
Laser Welding ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Process Technology ◽  
Surface Appearance ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Lap Welding ◽  
Lap Welding

The development of automobile steel was analyzed in this paper; it is pointed out that high-strength galvanized steel will be widely used in the car body structure. By analyzing welding problems about the dual phase (DP) series of high-strength galvanized steel, the importance of laser welding was concerned. Finally, laser lap welding process technology of high-strength galvanized steel was studied; the results show that the lap weld with welding process smooth and spatter-free as well as beautiful welding bead surface appearance and good mechanical properties can be made by using the dual-beam laser welding technology and interlayer for welding high-strength galvanized steel.

scholarly journals Porosity Characteristics and Effect on Tensile Shear Strength of High-Strength Galvanized Steel Sheets after the Gas Metal Arc Welding Process

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1077 ◽  
Author(s):  
Seungmin Shin ◽  
Sehun Rhee
Keyword(s):  
Shear Strength ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Tensile Test Specimen ◽  
Metal Arc Welding

In this study, lap joint experiments were conducted using galvanized high-strength steel, SGAFH 590 FB 2.3 mmt, which was applied to automotive chassis components in the gas metal arc welding (GMAW) process. Zinc residues were confirmed using a semi-quantitative energy dispersive X-ray spectroscopy (EDS) analysis of the porosity in the weld. In addition, a tensile shear test was performed to evaluate the weldability. Furthermore, the effect of porosity defects, such as blowholes and pits generated in the weld, on the tensile shear strength was experimentally verified by comparing the porosity at the weld section of the tensile test specimen with that measured through radiographic testing.

Noise Reduction During Acoustic Monitoring of Laser Welding of High-Strength Steels

2009 ◽  
Author(s):  
Wei Huang ◽  
Radovan Kovacevic
Keyword(s):  
Laser Welding ◽  
Noise Reduction ◽  
Acoustic Signal ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Weld Penetration ◽  
Acoustic Signatures ◽  
Reduction Methods ◽  
Laser Welding Process

During the laser welding process of high-strength steels, different defects, such as a partial weld penetration, spatters, and blow-through holes could be present. In order to detect the presence of defects and achieve a quality control, acoustic monitoring based on microphones is applied to the welding process. As an effective sensor to monitor the laser welding process, however, the microphone is greatly limited by intensive noise existing in the complex industrial environment. In this paper, in order to acquire a clean acoustic signal from the laser welding process, two noise reduction methods are proposed: one is the spectral subtraction method based on one microphone and the other one is the beamforming based on a microphone array. By applying these two noise reduction methods, the quality of the acoustic signal is enhanced, and the acoustic signatures are extracted both in the time domain and frequency domain. The analysis results show that the extracted acoustic signatures can well indicate the different weld penetration states and they can also be used to study the internal mechanisms of the laser-material interaction.

Deepstar Hull Fabrication

1965 ◽  
Vol 2 (04) ◽  
pp. 360-369
Author(s):  
George F. Gayer
Keyword(s):  
Salt Water ◽  
Water Environment ◽  
Welding Process ◽  
High Strength ◽  
Automatic Welding ◽  
Electric Motors ◽  
Camera Port ◽  
Ac Power ◽  
Welding Alloy ◽  
Private Venture

Deepstar is a self-propelled, manned vehicle for deep-sea research. It is being built as a private venture by Westinghouse Underseas Division, Baltimore, under a technical exchange license with Captain Cousteau and the OFRS (Office Francais de Recherches Sous-Marines) of Marseilles, France. Deepstar is designed to carry a crew of three to depths of 4000 ft for periods up to 24 hr. It is powered by two 4½-hpbattery-operated electric motors which propel it at about 3 knots, with a maximum range of about 20 miles. Overall dimensions of the vehicle are 13 ft long by 7 ft high by 11½ft wide over the fairing. The pressure sphere which houses the crew was built for our Baltimore Underseas Division by Westinghouse, Sunnyvale Marine Division. It measures 70 in. od and was fabricated from two hemispheres of high-strength steel. These hemispheres were spun from alloy plates 1?in. and then machined both inside and outside to 1.2 in. thick. Accurate machining was essential to maintain the sphericity required for pressure stability. After machining, the two hemispheres were welded together by an automatic welding process. The sphere has a total of 11 penetrations through the shell, including an access hatch, 2 viewports, a camera port, 2 electrical passages and 5 shaft openings. Reinforcements for the larger openings were made by welding alloy-steel forgings into the shell. Small openings were reinforced by weld metal buildup through which holes were drilled. All reinforcements were then machined to provide accurate penetrations and sealing surfaces. An extensive metallurgical testing program was conducted to insure that all material and welding used in the sphere had the strength and toughness required for operation at maximum depths. Pressure tests have been conducted in a chamber to 1.2 maximum operating depth. Sunnyvale also made the electric motors for Deepstar. These free-flooded ac motors are suspended outside the pressure hull. Unusual problems solved by special processing included electrical insulation in the salt water environment and water-lubricated bearings. AC power for the motors is provided from the batteries through a rotary inverter with semi-conductor controls.

Comparison between Modelled Influence of GMAW Parameters and Corresponding Mechanical Properties of Group 1 and 2 According to ISO/TR 15608 Steel T Joints

2021 ◽  
Vol 890 ◽  
pp. 17-24
Author(s):  
Aurel Valentin Bîrdeanu ◽  
Alin Constantin Murariu ◽  
Horia Florin Daşcău ◽  
Iuliana Duma
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Hsla Steel ◽  
Welding Process ◽  
High Strength ◽  
Industrial Applications ◽  
Steel Plates ◽  
Experimental Program ◽  
Welding Parameters ◽  
T Joints

Reproducibility in respect to welded structures realization is one of the main requirements for a wide variety of industrial applications. One of the international tendencies regarding the use of the steel is the replacing, in critical areas, of structural steels with high performance steel, e.g. with HSLA steels. The paper presents the results of a factorial designed experimental program focused on determining mathematical correlations between the GMAW process parameters for T joints of 4mm thick steel plates of structural (S235JR+AR according to SR EN 10025-2) and hot-rolled, high-strength low-alloy (HSLA) steel plates (S420MC according to EN 10025-4), respectively. A comparison between the obtained mathematical correlations that connect the welding parameters and the main mechanical characteristics is presented. The correlations can be used for applying the optimal combination of welding process parameters for realizing the T-joints of welded products.

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