P355NL1
Weldable fine-grain structural steels
for pressure vessels
Material no. 1.0566 With cold-forming above 5% or hot-for- Chemical composition
analogic DIN EN 10028-3 ming outside of the temperature range (in percent by weight)
Tensile strength class B of 850 – 1.000 °C as well as after excess
times, the steels rolled under normalised min. max.
conditions should be subsequently nor- C 0,18
Usage malised at 900–950 °C. The holding time Si 0,50
These fine-grain structural steel after temperature equalisation should be Mn 1,10 1,70
grades are characterised by a minimum approx. 1 minute per millimetre of plate P 0,025
yield strength of 275-460 N/mm2, by good thickness. S 0,015
weldability and high resistance to brittle N 0,012 1)
cracking. These grades are used above Cu 0,30
all for manufacturing vessels for pressuri- Ni 0,50
sed gas (LPG, butane and propane tanks), Ti 0,030 2)
pressure vessels, steam boiler parts, pres- V 0,10
sure piping, compressors ect. Nb 0,050
Notch Impact energy Al 0,020
The following special grades are Minimum value of notch impact ener- 1) If N is additionally fixed by means of Nb, Ti or V,
available for extraordinary applications: gy1) [J] at a test temperature of [°C] the minimum Al content is not determined. If N is
only fixed with Al, then: Al/N ≥2.
– P. . . NL1 and P. . . NL2 or P. . . ML1 °C longitudinal [J] transverse [J] 2)Nb + V + Ti ≤0,12%
and P. . . ML2 for application tem +20°C ≥ 80 J ≥ 60 J
peratures below -20 °C 0°C ≥ 70 J ≥ 50 J
– P. . . NH for operating tempera -20°C ≥ 50 J ≥ 35 J
tures of up to 400 °C. -40°C ≥ 40 J ≥ 27 J
-50°C ≥ 30 J -
The user of these steel grades must A carbon equivalent value CE = C +
1) Average values of 3 samples; one individual value
make sure that his calculation, design and Mn/5 + (Cr + Mo + V)/5 + (Cu + Ni)/15
may fall short of the required minimum value by not
processing methods are appropriate for more than 30%. The sample width shall equal the may be agreed in th order, i.e. 0,40 %
the material. The welding technique used product thickness if the latter is between 5-10mm, max. for grades P275, 0,43% for grades
the test being performed using samples which are
must be suitable for the intended appli- similar to Charpy-V samples. The values specified P355N, 0,39% for grades P355M, 0,43%
cation and comply with the state-of-the- in the table above are to be reduced proportionally for grades P420 and 0,45 % for grades
art. to the sample width. P460.
The fine-grain strucutral steel grades
rolled under normalised conditions offer
good cold-forming and hot-forming pro-
perties without negatively affecting the
material properties. These steel grades
are therefore also suitable for cold-borde-
ring and cold-flanging as well as for cold-
bending and cold-folding, considering the
bending radii according to DIN 6935 for
a steel grade of corresponding strength.
Salzgitter Flachstahl GmbH · Eisenhüttenstraße 99 · 38239 Salzgitter
Phone +49 (0) 5341 21-2890 · Telefax +49 (0) 5341 21-8536
E-Mail flachstahl@salzgitter-ag.de · http://www.salzgitter-flachstahl.de
Salzgitter Flachstahl P355NL1 Page from 2 Edition: 06/06
P355NL1
Weldable fine-grain structural steels
for pressure vessels
Mechanical properties 1) Available dimensions ding.
Hot-rolled coils unpickled, mill edge In general, pre-heating prior to wel-
Nom. thick. e Yield strength R eL /Rp 0,2 ding or torch-cutting is not necessary. At
≤ 16 mm 355 MPa Thickn. in mm Width in mm outside temperature below +5 °C, pre-
> 16 mm 345 MPa 2,00 – 2,24 900 – 1400 heating to approx. 150 °C should be car-
2,25 – 2,49 900 – 1450 ried out.
Nom. thich. e Tensile strength Rm 2,50 – 2,99 900 – 1500 Subsequent normalised or stress reli-
490 – 630 MPa 3,00 – 3,99 900 – 1680 ef annealing with the grades rolled under
4,00 – 6,00 900 – 1750 normalised conditions is required only if
Nom. thick. e Min. total elongation 6,01 – 12,70 900 – 1750 called for in the regulations or if operating
22 % and manufacturing conditions make a re-
duction of the residual welding stresses
The samples for the tensile test are Hot-rolled slit strip appear useful. The thermo-mechanically
taken at right angles to rolling direction rolled steels are not suitable for normali-
unless the product width is opposed to Thichn. in mm Width in mm zing; stress relief annealing is possible.
this. 2,00 – 2,24 100 – 690 With stress relief annealing at 530–580
2,25 – 2,49 100 – 715 °C, the holding time should be 2 minutes
1) Transverse samples
2,50 – 2,99 100 – 740 per milimetre of plate thickness, not fall
3,00 – 4,50 100 – 800 short of 30 minutes and not significantly
4,50 – 6,00 116 – 800 exceed 60 minutes.
6,01 – 7,00 175 – 800 Excessively high annealing tempera-
7,01 – 8,00 233 – 800 tres or excessively long annealing times
bear the risk of reducing the strength va-
≤ 100 mm on request lues to below the condition of delivery.
In addition to this, the guidelines for
processing these steel grades according
to „Stahl-Eisen-Werkstoffblatt“ (Iron and
Welding steel material sheet) 088 must be obser-
The fine-grain structural steel grades ved.
of this series can be perfectly welded both
manually and using automatic equipment
by means of all known welding processes. Condition of delivery, scope of te-
However, the quality of the weld joint de- sting and certificate
pends on the welding process, the wel- The steel grades P275NH-P355NL2
ding conditions and the selection of the are delivered in a condition obtained by
correct filler metals. normalised rolling. The steels grades
The welding wires and electrodes ap- P355M-P460ML2 are delivered in a ther-
proved in this strength category must be momechanically-rolled condition. The
used as filler metals. Basic coated elc- provisions of EN 10028-2 and -5 shall
trodes are recommended for manual wel- apply for delivery and inspection.
Salzgitter Flachstahl GmbH · Eisenhüttenstraße 99 · 38239 Salzgitter
Telefon +49 (0) 5341 21-2890 · Telefax +49 (0) 5341 21-8536
E-Mail flachstahl@salzgitter-ag.de · http://www.salzgitter-flachstahl.de
Salzgitter Flachstahl P355NL1 Page from 2 Edition: 06/06
