scholarly journals Effect of welding parameters and the heat input on weld bead profile of laser welded T-joint in structural steel

2015 ◽  
Vol 27 (S2) ◽  
pp. S29002 ◽  
Author(s):  
Anna Unt ◽  
Antti Salminen
2011 ◽  
Vol 704-705 ◽  
pp. 1128-1132
Author(s):  
Di Xin Yang ◽  
Yuan Fang Sun

Hydraulic support is an important part of fully mechanized equipments. The constructional steels of hydraulic support with international advanced level mainly adopt the high-strength welding structural steel with its tensile strength of more than 700~1000MPa.This paper analyzes the chemical compositions features of S890 high-strength low alloy steel for 900MPa grade.The Influence of welding parameters,peak temperature and on the microstructures and mechanical properties of welding HAZ of S890 high-strength low alloy steel were investigated by thermo-simulated tests, The influence of welding heat input on the mechanical behaviors of the welded joint was also investigated. The results show that the microstructures of S890 steel change from tempered martensite to bainite and a little ferrite , pearlitic when welding heat input changes from low to high, and accompany the austenite grains coarsening ,so the impact toughness and hardness of welding HAZ at lower peak temperatures and shorter are higher than that at higher peak temperature and long . Welding HAZ produced by the second weld bead will overlap partially with the HAZ produced by the first weld bead. In this area, primitive microstructure tempers again or partial re-phase transformations and re-cools,but the area involved in the overlap is limited,so the influence on the properties of S890 steel is not obvious. In covered arc welding,the influence on the welded join strength of S890 steel is not distinct when heat input change in a certain scope, but the plasticity of the welded join falls off steeply as heat input increases. Keywords: S890 steel; high-strength low alloy steel; weld performance; hydraulic supports


2013 ◽  
Vol 465-466 ◽  
pp. 1370-1374 ◽  
Author(s):  
Abdullah Wagiman ◽  
Mohd Saidin Bin Wahab ◽  
Zazuli Mohid ◽  
Azuddin Mamat

In developing a new method for weld based freeform fabrication, parameter affecting the geometry of single-pass need to be determined as it has great influence on dimensional accuracy and mechanical property of metallic part. In this paper, profile geometry and microstructure of single pass weld bead developed using Gas Metal Arc Welding Cold Metal Transfer (GMAW-CMT) was investigated. Observation on cross sectional weld bead indicates GMAW-CMT has capability to produce free spatter and crack defect weld bead. Profile geometry measurement shows weld bead develop at higher heat input has width size larger than the weld bead develop at lower heat input. Microstructure examination in the substrate reveals formation of columnar dendritic, cellular and planar structure while at buildup layer exhibit equiaxed dendritic structure


2011 ◽  
Vol 383-390 ◽  
pp. 6247-6251 ◽  
Author(s):  
M. Moradi ◽  
M. Ghoreishi ◽  
M.J. Torkamany ◽  
J. Sabbaghzadeh ◽  
M.J. Hamedi

In the present study, a low average power pulsed Nd:YAG laser is used for bead-on-plate welding of low carbon steel plate. The effect of laser process parameters on the weld quality and weld bead profile, welding penetration (P), welding surface width (W) and welding pool area (A), is studied. Focal point position, welding speed, pulse duration, and energy are selected as the process variables. The formation of a keyhole and weld bead profile is found to be highly dependent on laser pulse parameters. Results show that the maximum penetration accurse when the focal point is above the surface, in pulse duration of 6 ms, welding speed of 2 mm/s and pulse energy of 16.67 J.


2014 ◽  
Vol 564 ◽  
pp. 549-554
Author(s):  
Nik Mohd Baihaki Abd Rahman ◽  
Abdul Ghalib Tham ◽  
Sunhaji Kiyai Abas ◽  
Razali Hassan ◽  
Yupiter H.P. Manurung ◽  
...  

A robotic system can convert the semi-automatic Flux Cored Arc Welding (FCAW) to an automatic welding system. The critical requirement in automated welding process is that the optimal welding parameter has to be set before welding start. These input welding parameters cannot be easily guessed unless one has the knowledge. Only very specific range of heat input that produces quality weld deposition. The correlation between the heat input and fillet weld bead can be displayed in a unique trend-line graph. Mathematical formulas that match the trend-line profile can be used to create a prediction calculator that displays the digital values of weld bead geometry when welded at a specific range of heat input. Small Mean Absolute Deviation between predicted and measured geometry means good prediction accuracy. With this correlation chart, the welding parameter for quality weld bead can be selected and the geometry of FCAW weld deposition in 2F position can be predicted accurately without trial and error.


Author(s):  
Elisan dos Santos Magalhães ◽  
Luiz Eduardo dos Santos Paes ◽  
Milton Pereira ◽  
Sandro Metrevelle Marcondes de Lima e Silva

SIMULATION ◽  
2021 ◽  
pp. 003754972110315
Author(s):  
B Girinath ◽  
N Siva Shanmugam

The present study deals with the extended version of our previous research work. In this article, for predicting the entire weld bead geometry and engineering stress–strain curve of the cold metal transfer (CMT) weldment, a MATLAB based application window (second version) is developed with certain modifications. In the first version, for predicting the entire weld bead geometry, apart from weld bead characteristics, x and y coordinates (24 from each) of the extracted points are considered. Finally, in the first version, 53 output values (five for weld bead characteristics and 48 for x and y coordinates) are predicted using both multiple regression analysis (MRA) and adaptive neuro fuzzy inference system (ANFIS) technique to get an idea related to the complete weld bead geometry without performing the actual welding process. The obtained weld bead shapes using both the techniques are compared with the experimentally obtained bead shapes. Based on the results obtained from the first version and the knowledge acquired from literature, the complete shape of weld bead obtained using ANFIS is in good agreement with the experimentally obtained weld bead shape. This motivated us to adopt a hybrid technique known as ANFIS (combined artificial neural network and fuzzy features) alone in this paper for predicting the weld bead shape and engineering stress–strain curve of the welded joint. In the present study, an attempt is made to evaluate the accuracy of the prediction when the number of trials is reduced to half and increasing the number of data points from the macrograph to twice. Complete weld bead geometry and the engineering stress–strain curves were predicted against the input welding parameters (welding current and welding speed), fed by the user in the MATLAB application window. Finally, the entire weld bead geometries were predicted by both the first and the second version are compared and validated with the experimentally obtained weld bead shapes. The similar procedure was followed for predicting the engineering stress–strain curve to compare with experimental outcomes.


Author(s):  
Hannah Schönmaier ◽  
Ronny Krein ◽  
Martin Schmitz-Niederau ◽  
Ronald Schnitzer

AbstractThe alloy 2.25Cr-1Mo-0.25V is commonly used for heavy wall pressure vessels in the petrochemical industry, such as hydrogen reactors. As these reactors are operated at elevated temperatures and high pressures, the 2.25Cr-1Mo-0.25V welding consumables require a beneficial combination of strength and toughness as well as enhanced creep properties. The mechanical properties are known to be influenced by several welding parameters. This study deals with the influence of the heat input during submerged-arc welding (SAW) on the solidification structure and mechanical properties of 2.25Cr-1Mo-0.25V multilayer metal. The heat input was found to increase the primary and secondary dendrite spacing as well as the bainitic and prior austenite grain size of the weld metal. Furthermore, it was determined that a higher heat input during SAW causes an increase in the stress rupture time and a decrease in Charpy impact energy. This is assumed to be linked to a lower number of weld layers, and therefore, a decreased amount of fine grained reheated zone if the multilayer weld metal is fabricated with higher heat input. In contrast to the stress rupture time and the toughness, the weld metal’s strength, ductility and macro-hardness remain nearly unaffected by changes of the heat input.


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