scholarly journals Welding of Thermomechanically Rolled Fine-Grain Steel by Different Types of Lasers/ Spawanie Stali Drobnoziarnistej Walcowanej Termomechanicznie Laserami Różnego Typu

2014 ◽  
Vol 59 (4) ◽  
pp. 1625-1631 ◽  
Author(s):  
A. Lisiecki

Abstract The autogenous laser welding of 2.5 mm thick butt joints of thermomechanically rolled fine-grain steel grade S420MC was investigated. Butt joints were laser welded by the Yb:YAG Disk laser, emitted a circular laser beam with spot diameter of 200 μm at 1.03 μm wavelength, and also by the high power direct diode laser, emitted a rectangular beam with dimension of 1.8x6.8 mm at 808 nm wavelength. Different welding modes were identified for the lasers applied. The conduction welding mode was observed in whole of the diode laser welding parameters. While high quality joints, without any internal defects and characterized with satisfactory mechanical performance were produced in a wide range of parameters. The butt joints produced by Disk laser were welded at keyhole mode. In this case a slight tendency to weld porosity was found.

2016 ◽  
Vol 61 (1) ◽  
pp. 93-102 ◽  
Author(s):  
A. Lisiecki

The paper presents a detailed analysis of the influence of heat input during laser bead-on-plate welding of 5.0 mm thick plates of S700MC steel by modern Disk laser on the mechanism of steel penetration, shape and depth of penetration, and also on tendency to weld porosity formation. Based on the investigations performed in a wide range of laser welding parameters the relationship between laser power and welding speed, thus heat input, required for full penetration was determined. Additionally the relationship between the laser welding parameters and weld quality was determined.


2015 ◽  
Vol 60 (4) ◽  
pp. 2913-2922 ◽  
Author(s):  
A. Lisiecki ◽  
R. Burdzik ◽  
G. Siwiec ◽  
Ł. Konieczny ◽  
J. Warczek ◽  
...  

Autogenous laser welding of 0.8 mm thick butt joints of car body electro-galvanized steel sheet DC04 was investigated. The Yb:YAG disk laser TruDisk 3302 with the beam spot diameter of 200 μm was used. The effect of laser welding parameters and technological conditions on weld shape, penetration depth, process stability, microstructure and mechanical performance was determined. It was found that the laser beam spot focused on the top surface of a butt joint tends to pass through the gap, especially in the low range of heat input and high welding speed. All test welds were welded at a keyhole mode, and the weld metal was free of porosity. Thus, the keyhole laser welding of zinc coated steel sheets in butt configuration provides excellent conditions to escape for zinc vapours, with no risk of porosity. Microstructure, microhardness and mechanical performance of the butt joints depend on laser welding conditions thus cooling rate and cooling times. The shortest cooling time t8/5 was calculated for 0.29 s.


2017 ◽  
Vol 62 (3) ◽  
pp. 1651-1657 ◽  
Author(s):  
A. Kurc-Lisiecka ◽  
J. Piwnik ◽  
A. Lisiecki

AbstractThe article presents results of investigations on autogenous laser welding of new grade STRENX 1100 MC steel. The modern Disk laser was applied for of 5.0 mm thick butt joints welding. The influence of laser welding parameters, mainly the energy input of laser welding on the penetration shape, weld quality, structure and mechanical performance was investigated. It was found that the investigated steel has surprisingly low carbon equivalent CET just 0.328, and also relatively high temperature of martensitic transformation Msat 430.6°C. Despite very rapid cooling times t8/5in a range from 0.6 to 1.3 s, thus rapid solidification there was no tendency to cracking of weld metal or HAZ. Significant drop of microhardness in the HAZ resulted in a decrease of tensile strength of joints, compared to the base metal. Impact toughness of test joints was at only 50÷60% of the base metal.


2015 ◽  
Vol 60 (4) ◽  
pp. 2851-2860
Author(s):  
A. Lisiecki

Autogenous laser welding of 5.0 mm thick butt joints of thermomechanically rolled steel S700MC was investigated. The Yb:YAG disk laser TruDisk 3302 emitted at 1.03 μm was used for the trials of autogenous welding. The effect of laser welding parameters and thus thermal conditions of welding on weld shape, microstructure of weld metal and heat affected zone (HAZ), tensile strength, bending angle, impact toughness and microhardness profile was determined. Studies have shown that it is advantageous to provide a high welding speed and low heat input. High cooling rate of weld metal and HAZ leads to the formation of a favorable structure characterized by a large proportion of fine-grained acicular ferrite and provides high mechanical properties of butt joints.


Author(s):  
Yoshikazu SUITA ◽  
Kenji TANAKA ◽  
Masato OHTANI ◽  
Shinichiro SHOBAKO ◽  
Noboru TERAJIMA ◽  
...  

2005 ◽  
Vol 247 (1-4) ◽  
pp. 300-306 ◽  
Author(s):  
Jinhong Zhu ◽  
Lin Li ◽  
Zhu Liu

Author(s):  
Fabrizio Quadrini ◽  
Loredana Santo ◽  
Federica Trovalusci

Sign in / Sign up

Export Citation Format

Share Document