scholarly journals Study of Solidification Cracking Susceptibility during Laser Welding in an Advanced High Strength Automotive Steel

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 673 ◽  
Author(s):  
Gautam Agarwal ◽  
He Gao ◽  
Murugaiyan Amirthalingam ◽  
Marcel Hermans
Keyword(s):  
Laser Welding ◽  
High Strength ◽  
Free Edge ◽  
Processing Parameters ◽  
Solidification Cracking ◽  
Transverse Strain ◽  
Cracking Behavior ◽  
Steel Sheets ◽  
Weld Solidification Cracking ◽  
Automotive Steel

Susceptibility to weld solidification cracking in transformation-induced plasticity steel sheets was studied using a modified standard hot cracking test used in the automotive industry. To vary the amount of self-restraint, bead-on-plate laser welding was carried out on a single-sided clamped specimen at increasing distances from the free edge. Solidification cracking was observed when welding was carried out close to the free edge. With increasing amount of restraint, the crack length showed a decreasing trend, and at a certain distance, no cracking was observed. With the aid of a finite element-based model, dynamic thermal and mechanical conditions that prevail along the transverse direction of the mushy zone are used to explain the cracking susceptibility obtained experimentally. The results indicate that the transverse strain close to the fusion boundary can be used as a criterion to predict the cracking behavior. The outcome of the study shows that optimum processing parameters can be used to weld steels closer to the free edge without solidification cracking.

Laser Assisted Cold Bending of High Strength Steels

2014 ◽  
Author(s):  
Erica Liverani ◽  
Alessandro Ascari ◽  
Alessandro Fortunato ◽  
Adrian Lutey
Keyword(s):  
Heat Treatment ◽  
High Strength Steels ◽  
High Strength ◽  
Processing Parameters ◽  
Cold Forming ◽  
Steel Sheets ◽  
Phase Lead ◽  
Cold Bending ◽  
Bending Process ◽  
Definition Of

This paper presents the feasibility of an innovative application of laser-assisted bending process. The high strength steel sheets bending, carried out after a laser heat treatment, is studied. Several strategies aimed at obtaining a ductile structure along the bending line, suitable for cold forming, are investigated. The influence of laser processing parameters on the microstructure, hardness and strength of the sheets are discussed and analyzed. In order to predict the temperature and ensure the repeatability and reliability of the process, a model for heat treatment simulation is developed. The study of the experimental data and the integration with the simulation of the heating phase lead to the definition of specific process parameters suitable for achieving a crack-free cold bending of high strength steels.

Research on laser welding of high-strength galvanized automobile steel sheets

2009 ◽  
Vol 47 (11) ◽  
pp. 1117-1124 ◽  
Author(s):  
Lifang Mei ◽  
Genyu Chen ◽  
Xiangzhong Jin ◽  
Yi Zhang ◽  
Qiang Wu
Keyword(s):  
Laser Welding ◽  
High Strength ◽  
Steel Sheets ◽  
Automobile Steel

scholarly journals Modeling of Surface Crack Defects Developed on Shear Edge in High-strength Automotive Steel Sheets

2020 ◽  
Vol 60 (1) ◽  
pp. 143-152
Author(s):  
Sota Goto ◽  
Kazuhiko Yamazaki ◽  
Thi-Huyen Doan ◽  
Yoshimasa Funakawa ◽  
Osamu Umezawa
Keyword(s):  
Surface Crack ◽  
High Strength ◽  
Steel Sheets ◽  
Shear Edge ◽  
Automotive Steel

scholarly journals Evaluation of solidification cracking susceptibility during laser welding in advanced high strength automotive steels

2019 ◽  
Vol 183 ◽  
pp. 108104 ◽  
Author(s):  
G. Agarwal ◽  
A. Kumar ◽  
I.M. Richardson ◽  
M.J.M. Hermans
Keyword(s):  
Laser Welding ◽  
High Strength ◽  
Solidification Cracking

scholarly journals MECHANICAL PROPERTIES LASER WELDING AUTOMOTIVE STEEL SHEETS

2015 ◽  
Vol 21 (3) ◽  
pp. 195
Author(s):  
Anna Lišková ◽  
Mária Mihaliková ◽  
Lukáš Dragošek ◽  
Róbert Kočiško ◽  
Róbert Bidulský
Keyword(s):  
Mechanical Properties ◽  
Laser Welding ◽  
Welded Joints ◽  
Metallographic Analysis ◽  
Interstitial Free ◽  
Steel Sheets ◽  
Interstitial Free Steel ◽  
Thin Steel ◽  
Micro Alloyed Steel ◽  
Automotive Steel

<p>The experimental and theoretical investigation deals with laser welding of automotive thin steel sheets. As tested materials were used Interstitial Free Steel (IF) from type of Hight Strength Low Alloy (HSLA) and the second is S420 steel (Micro-Alloyed Steel). Changes of properties of these materials were carried out by static dynamic conditions. The structure of welded joints these two materials were investigated by metallographic analysis. Metallographic analysis confirmed the formation of favourable structure of weld metal and heat affected zone. Obtained results showed that by laser welding it is possible to create the high quality welded joints with positive mechanical properties on used in automotive industry.</p>

scholarly journals Microstructural Aspects of Twin-Spot Laser Welding of Dp-Hsla Steel Sheet Joints

2016 ◽  
Vol 61 (2) ◽  
pp. 731-740 ◽  
Author(s):  
S. Stano ◽  
A. Grajcar ◽  
Z. Wilk ◽  
M. Różański ◽  
P. Matter ◽  
...  
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Power Distribution ◽  
Steel Sheet ◽  
Hsla Steel ◽  
High Strength ◽  
Geometrical Parameters ◽  
Steel Sheets ◽  
Welding Head ◽  
Steel Joints

Abstract The article presents the possibility of using twin-spot laser welding (i.e. laser welding with focusing a laser beam on two spots) for making overlap joints made of 0.8-1 mm thick HSLA and DP type high strength steel sheets. Joints were made using a Yb:YAG disc laser having a maximum power of 12 kW and a welding head by means of which it was possible to focus a laser beam on two spots, 0.6 mm and 1 mm away. The angle between focuses amounted to 0° or 90°, whereas the power distribution was 50%-50%. With settings as presented above it was possible to obtain high-quality overlap joints. The geometrical parameters of the joints were primarily affected by beams positions (in relation to each other) and, to a lesser degree, by the distance between the focuses. It was possible to obtain a 10% hardness reduction in the fusion zone of the DPHSLA steel joints if the angle between the beams amounted to 90°. The tests also involved microstructural examinations of individual zones of the joints

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