S235J2W+N is a structural steel with improved atmospheric corrosion
resistance. Due to its chemical composition, this material develops
a patina with increased resistance against the atmospheric
corrosion in comparison with non-alloyed structural steels.
Due to its restricted chemical composition, S235J2W+N STRUCTURAL
STEEL has a better weldability compared to respective steels
produced according to EN 10025-5.
S235J2W+N STRUCTURAL STEEL is used for instance in steel
constructions like bridges and buildings.
Product description
Designation and range of application
S235J2W+N STRUCTURAL STEEL can be delivered in thicknesses from 8
to 150 mm according to our delivery program. Other dimensions are
available on request.
S235J2W+N STRUCTURAL STEEL (material number 1.8961), specified in
EN 10025-5. Under the designation S235J2W+N STRUCTURAL
STEEL/S235J2W+N, CE-marking will be applied in thicknesses up to
150 mm according to EN 10025-1.
Under the designation S235J2W+N STRUCTURAL STEEL/S235J2W+N, the
„marque NF-Acier“ (class 2 or 21) can be applied in thicknesses up
to 150 mm according to NF EN 10025-5.
Chemical composition
For the ladle analysis the following limiting values are applicable
in %:
| C | Si | Mn | P | S | Cu | Cr | Ni | Nb | V | Al |
| ≤0.13 | ≤0.40 | 0.20-0.60 | ≤0.020 | ≤0.005 | 0.25-0.40 | 0.40-0.60 | ≤0.40 | ≤0.040 | ≤0.08 | ≥0.020 |
Delivery condition
Normalized or normalizing rolling in accordance with EN 10025-5.
Mechanical and technological properties in the delivery condition
Tensile test at ambient temperature – transverse test
Plate thickness t [mm] | Minimum yield strength (a) ReH [MPa] | Tensile strength Rm [MPa] | Minimum elongation A5 [%] |
| t ≤ 16 | 235 | 360-510 | 24 |
| 16 < t ≤ 40 | 225 |
| 40 < t ≤ 63 | 215 | 23 |
| 63 < t ≤ 100 | 22 |
| 100 < t ≤ 150 | 195 | 350-500 |
(a) If not apparent, the yield strength Rp0.2 is measured.
Impact test on Charpy-V-longitudinal specimens
| Absorbed energy KV2 [J] at a test temperature of -20 °C |
| Average of 3 tests | Single value |
| 27 | 19 |
The specified minimum value is the average of 3 tests. One
individual value may be below the minimum average value specified,
provided that it is not less than 70 % of that value. For plate
thicknesses ≤ 12 mm the test can be carried out on Charpy-V-test
specimens with reduced width, the minimum width of the specimens
being 5 mm. Then, the minimum impact value decreases proportionally
to the section of the test specimen.
Weld bead bend test
For plate thickness > 30 mm, S235J2W+N STRUCTURAL STEEL can be
delivered with additional weld bead bend test in accordance with
SEP 1390 (edition 1996) if specified at the time of the order
(option 1).
Testing
Tensile and impact tests will be performed according to EN 10025-5
once per heat, 40 t and thickness range as specified for the yield
strength. If agreed at the time of the order, the tests could be
performed on each mother plate (option 2).
The preparation of the test units occurs in accordance with EN
10025-1 and EN10025-5. The tensile test is carried out in
accordance with EN ISO 6892-1.
The impact test is carried out at -20 °C on longitudinal
Charpy-V-specimens using a 2 mm striker in accordance with EN ISO
148-1.
Unless otherwise agreed, the test results are documented in a
certificate 3.1 in accordance with EN 10204.
Order options
1) Weld bead bend test in accordance with SEP 1390 (Edition 1996),
2) Verification of the tensile and impact properties on each mother
plate.
Plate identification
Unless otherwise agreed, the marking is carried out via steel
stamps with at least the following information:
· Steel designation (S235J2W+N STRUCTURAL STEEL/S235J2W+N)
· Heat number
· Number of mother plate and individual plate
· Identification mark of the manufacturer
· Identification mark of the authorized inspection representative
Atmospheric corrosion resistance
Atmospheric corrosion resistance means that S235J2W+N STRUCTURAL
STEEL - due to its chemical composition - presents an improved
resistance against atmospheric corrosion because of the forming of
an auto- protective layer on the base material depending on weather
condition having a succession of dry and wet periods. This layer
protects the surface and slows down the normal rust formation.
Generally, the corrosion velocity decreases with increasing service
life. Even after the formation of the patina, a total stop of the
corrosion process does not occur.
However, the patina offers - in comparison to unalloyed steels - a
better protection against atmospheric corrosion in industrial, city
or rural atmospheres, enabling the application of uncoated steels
under certain circumstances.
Initial formation, time of development and protective effect of the
patina on steels with improved atmospheric corrosion resistance are
extremely depending on the constructional design and the
atmospheric and environmental conditions in the respective case.
Processing
The entire processing and application techniques are of fundamental
importance to the reliability of the products made from this steel.
The user should ensure that his design, construction and processing
methods are aligned with the material, correspond to the
state-of-the-art that the fabricator has to comply with and are
suitable for the intended use. The customer is responsible for the
selection of the material. The recommendations in accordance with
EN 1011-2.
Cold forming
Cold forming means forming below the maximum allowable stress
relief temperature (generally < 580 °C).
S235J2W+N STRUCTURAL STEEL can be cold formed as any comparable
structural steel in accordance with EN 10025. In case of higher
cold forming ratios, i.e. edging on mechanical presses, it is
advisable to consult the steel manufacturer prior to placing the
order.
Hot forming
Hot forming means forming at temperatures above AC3 (~ 900 °C;
austenitic phase). If possible, the hot forming has to be carried
out at the normalizing temperature with following cooling in still
air.
Flame cutting and welding
S235J2W+N STRUCTURAL STEEL has an excellent weldability under the
condition that the general technical rules (see EN 1011) are
observed. The fabrication by flame cutting and welding has to be
carried out similarly to normal unalloyed structural steels of EN
10025 of the same strength and dimensions. However the
hardenability of the steel is increased due to the Cu and Cr
alloying. The preheat conditions must be adapted to the carbon
equivalent. If necessary, the corrosion resistance of the welding
deposit has to be assured by selection of adequate weld metals or
other anti-corrosion measures.
Heat treatment
Welded joints of S235J2W+N STRUCTURAL STEEL are usually used in
welded condition. If a stress relief heat treatment is necessary, a
temperature of maximum 580 °C and a holding time of maximum 60
minutes with a heating and cooling speed of 70 - 80 °C/h is
recommended.
General technical delivery requirements
Unless otherwise agreed, the general technical delivery
requirements in accordance with EN 10021 apply.
Tolerances
Unless otherwise agreed, tolerances are in accordance with EN
10029, class A for the thickness and table 4, steel group L, for
the maximum flatness tolerance. Smaller flatness tolerances can be
agreed at the time of the order.
Surface quality
Unless otherwise agreed, the specifications will be in accordance
with EN 10163-2, class A2.
General notes
If particular requirements are demanded and not covered in this
material data sheet, please contact us with the specifications for
our review and agreement prior to ordering.
Production process
