QStE - WINFA sro

QSTE...
hot-rolled high strength cold forming
sheet steel as per
EN 10 149
QStE – hot-rolled high
strength cold forming sheet
steel
Steels labelled QStE are a class of fine
grain micro-alloyed thermo-mechanically rolled
(TM) steels. They are suitable for cold forming
due to their high strength.
The labelling of these steels can differ with
different producers (Table 1). They can be
labelled as ALFORM355M to ALFORM650M,
S355MC to S700MC, RAEX355MC OPTIM to
RAEX 700MC OPTIM, DOMEX355MC to
DOMEX700MC, YMPRESS E355 to
YMPRESSE690, KODUR355 to KODUR550,
etc. Each are labelled respective to Re yield
strengths.
Grades of QStE class steels are labelled
with three digits, expressing the value of the
minimal yield strength (Re) measured
perpendicularly to the direction of rolling. These
range from 380MPa to 690MPa according to the
EN 10 149-2 standard. See Table 2.
All the mechanical
characteristics which result
in QStE class steels as
better and higher quality
when compared with
common grade steels, are
generated due to thermomechanical rolling, the
addition of micro-alloying elements (Nb, V, Ti),
and a very precise setting of rolling parameters.
See Chemical composition table (Table 3).
All manufactured steel sheets have to meet the
parameters given as per the EN 10 149-2
standard. QStE class steels (hot-rolled) are
manufactured from the thickness of 2mm to
12mm in the form of slid strips or cut-to-length
sheets.
Utilisation
There are various applications of QStE
class steels. They have been used for:
• outrigger crane arms
• jib arms
• chassis constructions
• containers
• agriculture machinery etc.
The advantage of QStE steels is very little
use of alloying elements in the manufacturing
process (especially S and F), and this has a
positive effect on:
- a significantly lower carbon equivalent
(CEV>0,39), resulting in the improvement of steel
weldability
- excellent formability, even when it has to be
bent to tight radii and high steel strength
- high KV impact strength in low temperatures
- suitable for laser cutting
Advantages of usage
- less weight
- easier weldability
- simplified manufacturing
- robust design
- less environmental burden
- competitive edge
- economical efficiency
Benefits
When using higher or the highest grade of
QStE steels, specifically QStE690TM, the
following benefits can be attained in comparison
with QStE380TM steel sheets:
● with the same thickness of material, the new
design can
be as much
a s
2 x
stronger; i.e.
it can bear
2 x t h e
weight, or it
can endure
2x the load,
etc.
● while preserving the same construction
strength, a thinner steel sheet can be used,
resulting in
a decrease
of the
weight of
the
construction
by 25%, and
resulting in
many positive changes in the designing of new
steel constructions
for QStE steels, excellent cold forming is typical,
even when bent to
tight radii,
and this can
be a decisive
feature for
the design
applications
of materials
aiming at
economical
efficiency, demanding labour input, and static
characteristics of the product.
sheet can be bent to tight radii without cracking,
regardless of the direction of rolling (Table 4).
Shearing
QStE steels are well suited to cutting. There
is a rule that the highest tensile strength is, the
higher the power needed for cutting the material.
N a t u r a l l y, w i t h
increasing tensile
strength, tool wear
increases. Cutters
should be robust and
sharp, blades should
be slightly curved for
cutting, and there are
2 important parameters – shear gap ∆l and the
angle of the tool face. See Table 5.
Cutting
Laser cutting is a well
suited cutting technique
for QStE steels and due
to their chemical
composition no special
parameters are required.
Plasma cutting can be
used without any
limitations.
●
Bending
QStE steels
combine high
strength with good
bendability. Due to
lower carbon and
sulphur contents the
Machining
QSTE steels are, thanks to their chemical
composition, with some alloying elements
workable at all grades. In the lower grades
s p e c i f i c a l l y, Q S t E 3 8 0 T M , m a c h i n i n g
characteristics/ are
identical to S235 and S355
common steel grades. In
the highest QStE690TM
grades, high speed cutting
tools (HSS) must be used
for a smooth penetration
run of the tool into the
material. Specifically
during drilling, threading,
milling, etc., it is not necessary to adjust the speed
of revolutions or advancement. They can be
machined as any common material.
Tolerances
All grades of QStE steels are manufactured
in accordance with EN 10 051, which specifies
the tolerances on material thickness, dimensions
and flatness. All materials are supplied with a
certificate of the trials of the material mechanical
parameters as per EN 10 204, 3.1B.
as well – e.g. when
welding in lightly
stressed areas or when
welding high strength
steel to mild steel. For
more precise
information on
matching filler metals
see the Table below.
Welding
The weldability of QStE steels is excellent
even in the highest grades (QStE690 TM) due to
their chemical composition, and all methods of
welding can be used. Due to their low content of
alloying elements, the steels are not susceptible
to hot or cold cracking and therefore no
preheating of the steel is necessary. Matching
filler metals result in producing a weld that is as
strong as the steel itself. Under-matched filler
metals can be used
Weld
metal
RP
[MPa]
690
550
500
460
MMA
SAW
MIG/MAG
FCAW
Manual arc welding
Flux core wire welding
Protective atmosphere wire welding
Special wire welding
AWS A5.5
AWS A5.5
AWS A5.5
AWS A5.5
AWS A5.5
AWS A5.5
AWS A5.5
AWS A5.1
AWS A5.1
E 11018
E 11018
E 9018
E 8018
E 8016
E 7028
E 7018
E 7016
AWS A5.23
F11AXEX
AWS A5.28
ER 110S
AWS A5.29
E 11XT
AWS A5.23
AWS A5.23
AWS A5.23
AWS A5.23
AWS A5.17
F10AXEX
F9AXEX
F8AXEX
F7AXEX
F7AXEX
AWS A5.28
AWS A5.28
AWS A5.28
ER 100S
ER 90S
ER 80S
AWS A5.29
AWS A5.29
AWS A5.29
E10XT
E9XT
E 8XT
AWS A5.18
ER 70S
AWS A5.20
E 7XT
AWS A5.17
F7AXEX
AWS A5.18
ER 70S
AWS A5.20
E 7XT
QStE690TM
QStE550TM
QStE500TM
QSTE460TM
QStE380TM
380
Filler metals (AWS classes)
Recommended strength of weld metal
for abutting joint in cases where high weight-carrying
capacity crosswise to the weld joint is required
Strength of weld metal
for other welded joints
Table 1 Comparison of steel labelling
Comparison of steel labelling by different manufacturers
SEW 0921
EN 10 149 2
EN 10 149 2
QStE 380 TM
QStE 460 TM
QStE 500 TM
QStE 550 TM
QStE 690 TM
ALFORM 355M
ALFORM 460M
ALFORM 500M
ALFORM 550M
ALFORM 700M
S355MC
S460MC
S500MC
S550MC
S700MC
EN 10 149 2
RAEX 355 MC OPTIM
RAEX 460 MC OPTIM
RAEX 500 MC OPTIM
RAEX 550 MC OPTIM
RAEX 700 MC OPTIM
EN 10 149 2
EN 10 149 2
DOMEX 355 MC
DOMEX 460 MC
DOMEX 500 MC
DOMEX 550 MC
DOMEX 700 MC
CORUS RQT 501
CORUS RQT 601
CORUS RQT 701
1) Re is measured crosswise to rolling direction.
2) Re is measured length-wise to rolling direction.
Table 2 Selected values of typical mechanical properties as per EN 10 149-2
Mechanical properties
Grade
Re
[MPa]
Rm
[MPa]
A5
[%]
QStE 380 TM
QStE 460 TM
QStE 500 TM
QStE 550 TM
QStE 690 TM
355
460
500
550
700
430 – 550
520 – 670
550 – 700
600 – 760
750 – 950
23
17
14
14
12
KV
[°C]
-40
-40
-40
-40
-40
[ J]
40
40
27
27
27
Table 3 Typical values of chemical composition as per EN 10 149-2
Chemical composition
C
[%]
0,12
0,12
0,12
0,12
0,12
Grade
QStE 380 TM
QStE 460 TM
QStE 500 TM
QStE 550 TM
QStE 690 TM
Mn
[%]
1,5
1,6
1,7
1,8
2,1
Si
[%]
0,5
0,5
0,5
0,5
0,6
P
[%]
0,025
0,025
0,025
0,025
0,025
S
[%]
0,02
0,015
0,015
0,015
0,015
Al
[%]
0,015
0,015
0,015
0,015
0,015
Nb
[%]
0,09
0,09
0,09
0,09
0,09
V
[%]
0,2
0,2
0,2
0,2
0,2
Ti
[%]
0,15
0,15
0,15
0,15
0,22
Mo
[%]
0,5
B
[%]
0,005
Table 4 Bending as per EN 10 149-2
Material bending
Grade
QStE 380 TM
QStE 460 TM
QStE 500 TM
QStE 550 TM
QStE 690 TM
min. R of the bend
h = 3 – 6mm
0,5 x h
1,0 x h
1,5 x h
1,5 x h
2,0 x h
h < 3mm
0,25 x h
0,5 x h
1,0 x h
1,0 x h
1,5 x h
h > 6mm
1,0 x h
1,5 x h
2,0 x h
2,0 x h
2,5 x h
* some materials have min. radius of the bend by 50% smaller
Table 5 Shearing parameters
Shearing parameters
Grade
QStE 380 TM
QStE 460 TM
QStE 500 TM
QStE 550 TM
QStE 690 TM
shear gap ∆l
[%t]
7–9
7–9
7–9
8 – 11
11 – 14
the angle of the tool face
[°]
1–4
1–4
1–4
2–4
2–4
Senica
Trstín
Hlohovec
Bratislava
Senec
Bratislava
Žilina
Nitra
WINFA, s.r.o.
Skladová 2/A
917 00 TRNAVA
Slovak Republic
Trstínska cesta
917 00 TRNAVA
tel: +421 33 / 53 43 411
53 43 414
53 43 420
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