TY  - JOUR
A1  - Mukherjee, Krishnendu
A1  - Prahl, Ulrich
A1  - Bleck, Wolfgang
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
T1  - Characterization and modelling techniques for gas metal arc welding of DP 600 sheet steels
JF  - Materialwissenschaft und Werkstofftechnik
N2  - The objectives of the present work are to characterize the Gas Metal Arc Welding process of DP 600 sheet steel and to summarize the modelling techniques. The time-temperature evolution during the welding cycle was measured experimentally and modelled with the softwaretool SimWeld. To model the phase transformations during the welding cycle dilatometer tests were done to quantify the parameters for phase field modelling by MICRESS®. The important input parameters are interface mobility, nucleation density, etc. A contribution was made to include austenite to bainite transformation in MICRESS®. This is useful to predict the microstructure in the fast cooling segments. The phase transformation model is capable to predict the microstructure along the heating and cooling cycles of welding. Tensile tests have shown the evidence of failure at the heat affected zone, which has the ferrite-tempered martensite microstructure.
Y1  - 2010
U6  - http://dx.doi.org/10.1002/mawe.201000692
SN  - 1521-4052
VL  - 41
IS  - 11
SP  - 972
EP  - 983
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Mokrov, Oleg
A1  - Ahmed, Essam
T1  - Shielding gas influences on laser weldability of tailored blanks of advanced automotive steels
JF  - Applied surface science
N2  - The effects of shielding gas types and flow rates on CO2 laser weldability of DP600/TRIP700 steel sheets were studied in this work. The evaluated shielding gases were helium (He), argon (Ar) and different mixtures of He and Ar. Weld penetration, tensile strength and formability (Erichsen test) of laser welds were found to be strongly dependent upon the shielding gas types. The ability of shielding gas in removing plasma plume and thus increasing weld penetration is believed to be closely related to ionization potential and atomic weight which determine the period of plasma formation and disappearance. It was found that the higher helium shielding gas flow rate, the deeper weld penetration and the lower weld width.
Y1  - 2010
U6  - http://dx.doi.org/10.1016/j.apsusc.2010.08.042
SN  - 0169-4332 (E-Journal); 0169-4332 (Print)
VL  - 257
IS  - 5
SP  - 1401
EP  - 1406
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ahmed, Essam
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Mokrov, Oleg
T1  - On formability of tailor laser welded blanks of DP/TRIP steel sheets
JF  - Science and technology of welding and joining
N2  - This paper aims to evaluate the formability of tailor welded blanks of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets. In this work, bead on plate butt joints of 2·5 mm DP600 and 1·2 mm TRIP700 steel sheets were performed using CO2 laser beam welding. Microhardness measurements and transverse tensile testing were carried out to characterise the welds. The formability of base metals and welds were investigated by standard Erichsen test. In a perpendicular tensile test to the weld line, all specimens were fractured at the TRIP base metal, and the strengths were somewhat higher than those of base metal. There was a significant reduction in formability caused by welding of the DP600/TRIP700 steel sheets, and the formability increased with increasing welding speed.
Y1  - 2010
U6  - http://dx.doi.org/10.1179/136217110X12731414739754
SN  - 1743-2936
VL  - 15
IS  - 5
SP  - 337
EP  - 342
PB  - Maney
CY  - Leeds
ER  -