scholarly journals CFD-based modelling of phase transformation in laser welded low-carbon steel

2021 ◽  
Author(s):  
Aleksander Siwek
Keyword(s):  
Heat Source ◽  
Phase Transformations ◽  
Power Distribution ◽  
Low Carbon Steel ◽  
Marangoni Effect ◽  
Phase Changes ◽  
Test Material ◽  
Low Carbon ◽  
Welding Condition ◽  
Welding Pool

AbstractThis paper presents a numerical model of the laser welding of steel, taking into account the heat and mass flows, as well as thermal effects associated with phase transformations. It was assumed that the heat source is a laser with a symmetrical power distribution of the TEM10 beam in two welding condition variants: a stationary heat source and a source moving at a constant speed along the sample. After reaching the melting temperature, the movement of the liquid phase was forced by the Marangoni effect acting on the surface of the welding pool. For the laser power applied, the surface of the welding pool was assumed to be flat. It was proposed an algorithm for the forecasting of the phase changes during heating and cooling. Diffusive phase transformations during cooling were modelled using Johnson-Mehl-Avrami-Kolmogorov (JMAK) equations. Diffusionless transformations occurring when cooling rates exceed the critical ones were modelled using Koistinen-Marburger (KM) equations. Calculations were made for a rectangular sample welded in air and cooled spontaneously in the atmosphere. The boundary conditions were simulated assuming a constant coefficient of heat exchange and radiation to the environment. The start and end time of the changes occurring in the cooling phase were calculated based on the average cooling rate in the temperature range 800–500°C (v8/5). The model was tested for the test material: S355J2 steel.

scholarly journals Microstructure Examinations in Corners of the Low-Carbon Steel Slabs from Continuos Caster Machine

2016 ◽  
Vol 61 (4) ◽  
pp. 2051-2056 ◽  
Author(s):  
G. Kwinta ◽  
S. Kara ◽  
B. Kalandyk ◽  
R. Zapała ◽  
P. Pałka
Keyword(s):  
Surface Defects ◽  
Cast Steel ◽  
Continuous Process ◽  
Low Carbon Steel ◽  
Casting Process ◽  
American Petroleum Institute ◽  
Test Material ◽  
Low Carbon ◽  
Destructive Testing ◽  
Gaseous Fuels

Abstract The exposed selvedge layers in slabs cast by the continuous process should be free from surface defects, which in most cases appear in the form of cracks on the casting surface and run to its interior. In addition to the parameters of the casting process, the occurrence of such defects depends on the chemical composition of cast steel, on the segregation of surface active elements and formation of the precipitates of carbides, nitrides and other phases. Due to the frequent occurrence of defects in corners of the slabs, non-destructive testing was performed on the mechanically cleaned surfaces of slabs. The test material was low-carbon API(American Petroleum Institute API 5L standard) steel micro alloyed with Nb and Ti designed for the production of pipes to handle gas, oil and other liquid and gaseous fuels. Despite the use of different methods of inspection, i.e. ultrasonic, magnetic particle and penetrant, cracks were not traced in the examined material. Then, from the corners of the examined slabs, specimens were cut out for metallographic examinations. The main purpose of these examinations was to disclose the presence of possible cracks and micro cracks on the surfaces transversal and longitudinal to the direction of casting. At the same time, studies were conducted to establish the number and morphology of non-metallic inclusions in selvedge layers of the slab corners and axis. Additionally, hardness of the slabs was measured. The conducted studies revealed only some minor differences in the slab hardness along its axis (130 ÷ 135 HB) and in selvedge layers (120 ÷ 123 HB).

Phase transformations during the decomposition of austenite below M s in a low-carbon steel

2014 ◽  
Vol 95 ◽  
pp. 85-93 ◽  
Author(s):  
Elisabete Pinto da Silva ◽  
Wei Xu ◽  
Cecilia Föjer ◽  
Yvan Houbaert ◽  
Jilt Sietsma ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Phase Transformations ◽  
Low Carbon Steel ◽  
Low Carbon

J0470105 Effect of friction welding condition on tensile strength of friction welded joint between Ti-6Al-4V and low carbon steel

2015 ◽  
Vol 2015 (0) ◽  
pp. _J0470105--_J0470105-
Author(s):  
Masaaki KIMURA ◽  
Tsukasa IIJIMA ◽  
Masahiro KUSAKA ◽  
Koichi KAIZU ◽  
Akiyoshi FUJI ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Carbon Steel ◽  
Friction Welding ◽  
Welded Joint ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Welding Condition

‘Flash’ Annealing in a Cold-Rolled Low Carbon Steel Alloyed With Cr, Mn, Mo, and Nb: Part I - Continuous Phase Transformations

2018 ◽  
Vol 90 (1) ◽  
pp. 1800098 ◽  
Author(s):  
Felipe Manuel Castro Cerda ◽  
Florian Vercruysse ◽  
Constantinos Goulas ◽  
Bernd Schulz ◽  
Roumen H. Petrov
Keyword(s):  
Carbon Steel ◽  
Phase Transformations ◽  
Low Carbon Steel ◽  
Continuous Phase ◽  
Low Carbon ◽  
Flash Annealing ◽  
Cold Rolled

Isothermal Phase Transformations in a Low Carbon Steel During Single and Two-Step Partitioning

2020 ◽  
Vol 51 (4) ◽  
pp. 1506-1518
Author(s):  
F. M. Castro Cerda ◽  
E. I. Hernández ◽  
T. Ros-Yanez ◽  
R. H. Petrov
Keyword(s):  
Carbon Steel ◽  
Phase Transformations ◽  
Low Carbon Steel ◽  
Low Carbon

scholarly journals Microstructural Evaluation of the High-Frequency Induction Welded Joints of Low Carbon Steel Pipes

2021 ◽  
Vol 21 (4) ◽  
pp. 19-33
Author(s):  
Adam Bunsch ◽  
Janusz Krawczyk ◽  
Piotr Matusiewicz
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Structural Changes ◽  
Volume Fraction ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Phase Changes ◽  
Low Carbon ◽  
Structural Components ◽  
Microstructural Evaluation

Abstract The work presents the results of research on the structure of welded joints in the area of heat affected zone (HAZ). Based on precisely performed metallographic tests, the contribution of individual structural components in the area of welds of pipes welded with the induction method was assessed. The volume fraction of individual structural components in various areas of the heat affected zone, the size of the grain formed in the welding process, as well as its shape coefficients were determined. On the basis of metallographic observations, an attempt was made to describe the course of the pressure induction welding process, taking into account the structural changes, phase changes and the recovering and recrystallization processes taking place in this process.

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