Effect of Laser Welding on the Mechanical Properties AISI 1018 Steel

MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4031-4039 ◽  
Author(s):  
M. A. Carrizalez-Vazquez ◽  
M. Alvarez-Vera ◽  
A. Hernández-Rodríguez ◽  
J. M. Orona-Hinojos ◽  
Gabriel Sandoval-Vázquez ◽  
...  

AbstractLaser welding processes offer significant advantages such as high welding speed, narrow heat affected zone and quality of the welding joint. In this study, the process parameters of laser power and welding speed were modified for AISI 1018 steel plates of 8 mm thickness and compared using finite element method. The results of cross-section microstructure, heat affected zone and fusion zone were characterized. The grain refinement was affected as the parameters were modified. Tensile and microhardness tests were performed to determine the mechanical properties of the welding joints. Microhardness increased in fusion zone and decreased in heat affected zone. Tensile test showed ductile fracture in heat affected zone of the welding joints. The simulated profiles were compared with the experimental observations showing a reasonable agreement.

2014 ◽  
Vol 682 ◽  
pp. 91-95 ◽  
Author(s):  
Dmitry A. Chinakhov ◽  
A.V. Vorobyev ◽  
Yu.M. Gotovshchik

A set of various factors and phenomena defines the quality of welded joints. This is especially noticeable for outdoor welding. A numerical simulation of welding processes with consumable electrode with traditional and two-jet gas shielding was carried out to study the influence of wind speed on the movement of the shielding gas (CO2) and the change of thermal processes in the heat affected zone. It is established that the use of two-jet shielding in welding with a consumable electrode leads to an increase in hardness of the shielding gas stream and lower offset of thermal fields in the welded product in the wind direction. It testifies to a better quality of shielding and smaller probable changes in symmetry of structure formation and mechanical properties of the heat affected zone.


Author(s):  
I.C. MON ◽  
Mircea Horia ȚIEREAN ◽  
Liana Sanda BALTEȘ

This study highlights the weldability of austempered ductile iron (ADI) using laser welding. SEM, EDS and XRD analysis were performed on fusion lines, heat affected zone (HAZ) and melted zone (MZ). Welding speed (Ws) and laser power (P) were varied. The heat affected zone is composed of graphite, perlite and martensite; the melted and solidified zone contains graphite, ferrite and cementite. XRD results are in accordance with SEM micrographs.


2014 ◽  
Vol 496-500 ◽  
pp. 444-447 ◽  
Author(s):  
Zhi Hua Ma ◽  
Dong Gao Chen ◽  
Hong Wei Liu ◽  
Wu Lin Yang

Hybrid laser-Arc welding was to weld 20 mm thickness high nitrogen austenite stainless steel plates. Microstructure, hardness, mechanical properties and fractography of welding joints were researched. The results showed that the microstructure of heat affected zone and weld metal is austenite and δ-ferrite, and the heat-affected zone of welding joints is Narrow, its softening zone is smaller, the hardness is more uniform, the tensile strength of welding joints is 93.8% of the base material, fractured in the weld zone. The tensile fractography are obviously dimple.


2020 ◽  
Vol 856 ◽  
pp. 160-168
Author(s):  
Boonrit Kaewprachum ◽  
Pornsak Srisungsitthisunti

Understanding and predicting relationships between laser welding process parameters, such as laser power and welding speed, and molten pool have been studied widely in order to critically control and improve laser welding. The laser welding processes are difficult to monitor in real time because of high temperature and rapid heating characteristics. In this study, infrared camera was set to collect data and provide real time monitoring system to determine the molten pool characteristics and weld quality. This study carried out a laser welding of SS400 low carbon steel and analyzed real-time image of the welding process to determine the average temperature of molten pool and calculate the size of molten pool. By varying the laser power and the welding speed, the infrared camera and imaging processing technique can monitor change of molten pool temperature in a range of 1000 C to 15000 C with about 1% temperature fluctuation. In addition, the size of molten pool can be calculated from the temperature profile of the welding zone. The calculated molten pool size was about 95% accurate compared to the measured size from microscope imaging.


2016 ◽  
Vol 25 (43) ◽  
pp. 7-19 ◽  
Author(s):  
Minerva Dorta-Almenara ◽  
María Cristina Capace

Gas Tungsten Arc Welding (GTAW) is one of the most used methods to weld aluminum. This work investigates the influence of welding parameters on the microstructure and mechanical properties of GTAW welded AA6105 aluminum alloy joints. AA6105 alloy plates with different percent values of cold work were joined by GTAW, using various combinations of welding current and speed. The fusion zone, in which the effects of cold work have disappeared, and the heat affected zone of the welded samples were examined under optical and scanning electron microscopes, additionally, mechanical tests and measures of Vickers microhardness were performed. Results showed dendritic morphology with solute micro- and macrosegregation in the fusion zone, which is favored by the constitutional supercooling when heat input increases. When heat input increased and welding speed increased or remained constant, greater segregation was obtained, whereas welding speed decrease produced a coarser microstructure. In the heat affected zone recrystallization, dissolution, and coarsening of precipitates occurred, which led to variations in hardness and strength.


2022 ◽  
Vol 905 ◽  
pp. 44-50
Author(s):  
Li Wang ◽  
Ya Ya Zheng ◽  
Shi Hu Hu

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.


2016 ◽  
Vol 254 ◽  
pp. 33-42
Author(s):  
Ioan Catalin Mon ◽  
Mircea Horia Tierean ◽  
Eugen Cicala ◽  
Michel Pilloz ◽  
Iryna Tomashchuk ◽  
...  

This paper studies the ductile iron (DI) weldability using laser welding. For performing an Yb:YAG continuous laser was used, with a maximum power of 6 kW. The parametrical window power (P) - welding speed (S) was explored by carrying out the fusion lines on ductile iron plates without preheating, to determinate areas of weldability (complete penetration, correct geometry) to allow further characterization. The criteria for selection of focus areas were the geometry of the fusion lines and the absence of the welding defects. The unsatisfactory domains were characterized by: collapse of the melted metal, incomplete penetration, low fusion lines quality (geometry, compactness). In present study, several values of power and welding speed have been tested to identify their influence on geometry, compactness of the joints and mechanical properties. As result, the power-welding speed diagram for feasible domains of laser welding was generated.


2014 ◽  
Vol 974 ◽  
pp. 169-173 ◽  
Author(s):  
Imed Miraoui ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar

In the present study, high-power CO2 laser cutting of steel plates has been investigated and the effect of the input laser cutting parameters on the cut surface quality is analyzed. The average roughness of the cut surface of the specimens, produced by different laser beam diameter and laser power, were measured by using roughness tester. The scanning electron microscopy SEM is used to record possible metallurgical alterations on the cut edge. The aim of this work is to investigate the effect of laser beam diameter and laser power on the cut surface roughness and on the heat affected zone width HAZ of steel plates obtained by CO2 laser cutting. An overall optimization was applied to find out the optimal cutting setting that would improve the cut surface quality. It was found that laser beam diameter has a negligible effect on surface roughness but laser power had major effect on roughness. The cut surface roughness decreases as laser power increases. Improved surface roughness can be obtained at higher laser power. Also, laser beam diameter and laser power had major effect on HAZ width. It increases as laser power increases.


2021 ◽  
Vol 1018 ◽  
pp. 13-22
Author(s):  
Zhi Guo Gao

The thermal metallurgical modeling of liquid aluminum supersaturation was further developed through couple of heat transfer model, dendrite selection model, multicomponent dendrite growth model and nonequilibrium solidification model during three-dimensional nickel-based single-crystal superalloy weld pool solidification. The welding configuration plays more important role in supersaturation of liquid aluminum, morphology instability and nonequilibrium partition behavior. The bimodal distribution of liquid aluminum supersaturation along the solid/liquid interface is crystallographically symmetrical about the weld pool centerline in (001) and [100] welding configuration. The distribution of liquid aluminum supersaturation along the solid/liquid interface is crystallographically asymmetrical throughout the weld pool in (001) and [110] welding configuration. Optimum low heat input (low laser power and high welding speed) with (001) and [100] welding configuration is more favored to predominantly promote epitaxial [001] dendrite growth to reduce the metallurgical factors for solidification cracking than that of high heat input (high laser power and slow welding speed) with (001) and [110] welding configuration. The lower the heat input is used, the lower supersaturation of liquid aluminum is imposed, and the smaller size of vulnerable [100] dendrite growth region is incurred to ameliorate solidification cracking susceptibility and vice versa. The overall supersaturation of liquid aluminum in (001) and [100] welding configuration is beneficially smaller than that of (001) and [110] welding configuration regardless of heat input, and is not thermodynamically relieved by gamma prime γˊ phase. (001) and [110] welding configuration is detrimental to weldability and deteriorates the solidification cracking susceptibility because of unfavorable crystallographic orientations and alloying aluminum enrichment. The mechanism of asymmetrical solidification cracking because of crystallography-dependent supersaturation of liquid aluminum is proposed. The eligible solidification cracking location is particularly confined in [100] dendrite growth region. Moreover, the theoretical predictions agree well with the experiment results. The useful modeling is also applicable to other single-crystal superalloys with similar metallurgical properties for laser welding or laser cladding. The thorough numerical analyses facilitate the understanding of weld pool solidification behavior, microstructure development and solidification cracking phenomena in the primary γ phase, and thereby optimize the welding conditions (laser power, welding speed and welding configuration) for successful crack-free laser welding.


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