Analysis of laser-beam welded ultra-high-strength dual ...
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Annual Report 2017 89 Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01 Subject to alterations in specifications and other technical information. 08/2018. 2 Weld seam in S500MC/DP980 after buckling-bending load in the forming tool. 3 Fracture edge of a tensile specimen of DP1180 with micro voids elongated in the direction of flow. Results When the process parameters as well as the alloy range are adjusted to increase the critical temperatures, the width of the weakened area can be minimized. The positive effects can be supported by design features in order to shift critical points to less loaded positions. Applications The extended findings on the causes of failure can be applied to all weldable martensite-phase steels. This makes the know-how available for welding production in a wide range of applications, from vehicle construction for road and rail to structural steel construction. Contact Dipl.-Ing. Martin Dahmen Telephone +49 241 8906-307 [email protected] Dr. Dirk Petring Telephone +49 241 8906-210 [email protected] Task When dual-phase steels with strengths of 980 and 1180 MPa are laser welded, subcritical failure and localized deformation in the heat affected zone restrict their usability. By analyzing the thermally influenced zones, research can help understand the causes as well as contribute to defining corrective measures. Method As part of an error analysis, Fraunhofer ILT determined that annealing effects cause the material to weaken in the heat affected zone. At the same time, carbide precipitates strengthen the material in some areas. This development aimed to raise the minimum hardness in the heat affected zone and increase tempering resistance. In addition, an attempt was made to minimize the width of the annealing zone. ANALYSIS OF LASER BEAM WELDED ULTRA-HIGH-STRENGTH DUAL-PHASE STEELS 3 2
Transcript of Analysis of laser-beam welded ultra-high-strength dual ...
88 Annual Report 2017 Annual Report 2017 89
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Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de
DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01
Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de
DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01
Sub
ject
to
alt
erat
ion
s in
sp
ecifi
cati
on
s an
d o
ther
tec
hn
ical
info
rmat
ion
. 08/
2018
.
2 Weld seam in S500MC/DP980 after
buckling-bending load in the forming tool.
3 Fracture edge of a tensile specimen
of DP1180 with micro voids elongated
inthedirectionofflow.
Results
When the process parameters as well as the alloy range are
adjusted to increase the critical temperatures, the width of
the weakened area can be minimized. The positive effects can
be supported by design features in order to shift critical points
to less loaded positions.
Applications
The extended findings on the causes of failure can be applied
to all weldable martensite-phase steels. This makes the
know-how available for welding production in a wide range
of applications, from vehicle construction for road and rail to
structural steel construction.
Contact
Dipl.-Ing. Martin Dahmen
Telephone +49 241 8906-307
Dr. Dirk Petring
Telephone +49 241 8906-210
Task
When dual-phase steels with strengths of 980 and 1180 MPa
are laser welded, subcritical failure and localized deformation
in the heat affected zone restrict their usability. By analyzing
the thermally influenced zones, research can help understand
the causes as well as contribute to defining corrective measures.
Method
As part of an error analysis, Fraunhofer ILT determined
that annealing effects cause the material to weaken in the
heat affected zone. At the same time, carbide precipitates
strengthen the material in some areas. This development
aimed to raise the minimum hardness in the heat affected
zone and increase tempering resistance. In addition, an attempt
was made to minimize the width of the annealing zone.
ANALYSIS OF LASER BEAM WELDED ULTRA-HIGH-STRENGTH DUAL-PHASE STEELS
32
