Weldability of austempered rail steel using the flash-butt process

2021 ◽  
Vol 63 (7) ◽  
pp. 662-667
Author(s):  
Uğur Arabaci ◽  
Şafhak Turan
Keyword(s):  
Heat Treatment ◽  
Structural Steel ◽  
Rail Steel ◽  
Welding Parameters ◽  
Bainitic Steel ◽  
Butt Welding ◽  
Bainitic Microstructure ◽  
Bainite Structure ◽  
Treatment Changes

Abstract In this study, bainitic microstructure was formed via heat treatmenton R260 rail steel, which is generally used in railways. Bainitic steel, which is considered more advantageous than current rail steel, waswelded by flash butt welding, which is often used for joining rails andthe mechanical and microstructure of the samples were thenexamined and compared. Bainitic structural steel obtained by austempering heattreatment with normal rail steel was welded by flash butt welding. Flash-butt welding parameters were kept constant during the experiment. The welding capabilities of the joints were compared and the results wereevaluated. It was determined that the bainite structure obtained as a result of austempering heat treatment changes the microstructuralproperties of the samples and affects the mechanical values ​of the joints.

Tribological Properties of Rail Steel in Straight Moderately Loaded Sections of Railway Tracks

2011 ◽  
Vol 56 (3) ◽  
pp. 813-822 ◽  
Author(s):  
H. Bąkowski ◽  
A. Posmyk ◽  
J. Krawczyk
Keyword(s):  
Heat Treatment ◽  
Tribological Properties ◽  
Laboratory Tests ◽  
Structural Changes ◽  
Rail Steel ◽  
Railway Track ◽  
Bainitic Steel ◽  
Surface Layers ◽  
Railway Tracks ◽  
Fine Pearlite

Tribological Properties of Rail Steel in Straight Moderately Loaded Sections of Railway Tracks The paper describes the examination results of tribological properties of three types of steels used and suggested for rails manufacturing. The tests concentrated on loads, sliding and rolling speeds similar to those occurring in real conditions i.e. rolling track operation. Average loaded conditions were assumed and applied at straight railway track sections. Slight track declivity and high/low speeds of locomotive were considered. "Amsler" stand was used for laboratory tests. Three types of steels i.e. two pearlitic steels: WHT - without heat treatment, HT - with heat treatment (with the microstructure of fine pearlite) as well as one bainitic steel suggested for rail production have been tested. The measurements of wear, hardness, friction coefficient as well as structural changes at surface layers of the tested rollers have been performed during the test.

scholarly journals The formation оf the bainite structure during heat treatment of the rail steel (analogue J13052)

2016 ◽  
pp. 70-79
Author(s):  
Chertovskih Evgenii ◽  
◽  
Gabets Aleksandr ◽  
Gabets Denis ◽  
Markov Andrei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Rail Steel ◽  
Bainite Structure

scholarly journals Elaboration of a technology of long rail lashes production without induction heat treatment application

2019 ◽  
Vol 75 (4) ◽  
pp. 488-497
Author(s):  
N. A. Kozyrev ◽  
R. A. Shevchenko ◽  
S. N. Krat’ko ◽  
R. E. Kryukov ◽  
A. R. Mikhno
Keyword(s):  
Heat Treatment ◽  
Welded Joint ◽  
Rail Steel ◽  
Theoretical Calculations ◽  
Local Heating ◽  
Latency Period ◽  
Metal Structure ◽  
Butt Welding ◽  
Technical Requirements ◽  
Current Pulses

Welding butts of rail lashes after resistance butt-welding are subjected to heat treatment to eliminate heat-affected zones. At present facilities of induction heating are used in Russia for the heat treatment and compressed air as a quenching media. However, this method of quenching has significant drawbacks, including appearance of new heat-affected zones at the local heating of the welded butts, deterioration of the welded butts’ straightness after cooling. Shlatter Company proposed a solution of this problem by application of the process of resistance butt-welding by rails fusion. Theoretical calculations and laboratory studies of the thermal cycle of rail steel samples welding were made in the Siberian State Industrial University, which showed a principal possibility of this method application under industrial conditions. The method assumes after the welded butt settling and cooling to keep the preset temperature from the moment of its reaching by passing alternative electric current pulses through the welded butt. The temperature of exposure is selected based on obtaining necessary fine grain seam metal structure. The duration of exposure is determined by latency period of the structure formation and is controlled by the number of current pulses. The carried out industrial experiments at the МСР-6301 resistance butt welding machine resulted in determining parameters of cooling time after settling, heating and cooling after the heating, as well as the number of heating pulses. A method of resistance butt welding was tested, enabling to obtain the welded joint of details of the P65 ДТ350 category rail steel. The welded joint had mechanical properties exceeding technical requirements of СТО РЖД 1.08.002–2009 specifications.

Optimizing the welding parameters for Straight tube butt welding of dissimilar metals

2021 ◽  
Author(s):  
C. Ahilan ◽  
S. Santhosh Kumar ◽  
S. Ramesh Kumar ◽  
S. Abdul Gudoos ◽  
Senthil Kumaran Selvaraj
Keyword(s):  
Welding Parameters ◽  
Dissimilar Metals ◽  
Straight Tube ◽  
Butt Welding

Soviet Technique for Estimating Post-Welded Deflection: Case of Butt Welding

1989 ◽  
Vol 5 (01) ◽  
pp. 10-15
Author(s):  
V. Birman ◽  
R. Latorre
Keyword(s):  
Mathematical Theory ◽  
Critical Parameters ◽  
Welding Parameters ◽  
Plate Material ◽  
Butt Welding ◽  
Worked Example ◽  
Semi Empirical ◽  
Number Of Passes ◽  
Plate Geometry ◽  
Plate Deflection

The hulls of modern ships are almost entirely welded. This makes the prediction of post-welded deformations very important. The number of parameters involved in the process of welding is large, so the exact mathematical theory for prediction of deformations is unavailable. Some researchers have estimated the post-welded deflections based on empirical and semi-empirical equations. The growing literature on the study of postwelded deflections of hull plates enables the estimation of these deflections based on the plate geometry and the plate material. The limited number of critical parameters covered by these experiments makes it difficult to organize the data systematically. This has delayed the introduction of a framework for estimating the influence on the plate deflection from welding speed, current, number of passes, welding rod size and material, etc. The approach adopted in the U.S.S.R. was to develop an integrated framework to include the critical welding parameters. The main results from this approach were published in several books, with the main reference being a book by Kuzminov published in 1974. From the standpoint of ship production, it is useful to understand this Soviet approach as well as to give examples of its use. Therefore, this paper introduces the Soviet procedure for calculation of deflection due to butt welding, presents the graphical aids used in this procedure, and presents a worked example using this procedure for a butt welded plate.

scholarly journals Preliminary Research on Influence of Welding Parameters Strength at Welded Joints in Ribbed Reinforcing Steel

2020 ◽  
Vol 14 (3) ◽  
pp. 369-374
Author(s):  
Željko Bilić ◽  
Ivan Samardžić ◽  
Nedjeljko Mišina ◽  
Katarina Stoić
Keyword(s):  
Welded Joint ◽  
Welding Process ◽  
Welding Parameters ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Butt Welding ◽  
Control Interface ◽  
High Level ◽  
Non Destructive

As already known, no proper control or process control parameter which absolutely guarantees a high level quality of joints made by electro-resistive welding has been established so far, especially when all possible parameters are taken into account during the welding process. Due to the process of butt-welding being very short-lived, ensuring quality of the joints is a difficult and under-researched problem. The application of non-destructive testing methods to the control interface joints is also not reliable. Therefore, further research in this area should concentrate on studying the influence of basic welding parameters, and calculating their direct or indirect impact can serve to achieve a highquality welded joint with for practice sufficient accuracy.

scholarly journals Friction Stir Welding Parameters: Impact of Abnormal Grain Growth during Post-Weld Heat Treatment on Mechanical Properties of Al–Mg–Si Welded Joints

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1607
Author(s):  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar ◽  
Armin Rajabi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Friction Stir Welding ◽  
Grain Growth ◽  
Precipitation Hardening ◽  
Al Alloys ◽  
Abnormal Grain Growth ◽  
Post Weld Heat Treatment ◽  
Welding Parameters ◽  
Friction Stir

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.

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