![Logo und Homelink [Alt+1]](/0_image/logo_en_head.gif){kind=logo}
Information material
eService
more... | Register
Product range online
Newsletter
Services
Print version
Data protection
Imprint
Home
Weather resistant structural steels
Usage
These weather-resistant structural steel grades are used for manufacturing welded, riveted or bolted structures, e. g. in bridge, façade and vehicle construction. In general, the specific rust-building properties of Allwesta steel grades make surface protections of structures built of this steel grade unnecessary, provided that the 'Stahl-Eisen-Werkstoffblatt' (Iron and steel material sheet) 087 ‘Wetterfeste Baustähle, Richtlinien für die Lieferung, Verarbeitung und Anwendung’ (Weatherresistant structural steel, guidelines for delivery, processing and application) is observed.
The user of these steel grades must make sure that his calculation, design and processing methods are appropriate for the material and comply with the state-of-theart. The good properties of Allwesta steel grades are not negatively affected by cold or hot-forming. The minimum bending radii according to table 6 of DIN EN 10025-5 are recommended for cold-forming. Suitability for cold-forming must be agreed upon in the order.
If mechanical properties have been significantly modified by heavy coldforming, either stress relief annealing or normalised may be applied. Normalised should also be applied following hotforming outside of the temperature range of 750 - 1.050 °C and after overheating.
Standards
| Europe | Material no. | D | F | GB | USA | J | Salzgitter Flachstahl |
FK1) |
|---|---|---|---|---|---|---|---|---|
| EN 10025-5 | SEW 087 | NFA 35-502 | BS 4360 | ASTM | JIS G 3114 | |||
| S235J0W | 1.8958 | - | E 24 W 3 | - | - | - | Allwesta 360 | A |
| S235J2W | 1.8961 | WTSt 37-3 | E 24 W 4 | - | - | - | Allwesta 360 F | A |
| S355J0WP | 1.8945 | - | E 36 WA 3 | WR 50 A | - | - | Allwesta 510 P | B |
| S355J2WP | 1.8946 | - | E 36 WA 4 | - | A 242 Type 1 | - | Allwesta 510 FP | B |
| S355J0W | 1.8959 | - | E 36 WB 3 | WR 50 B | A 588 | SMA 50 AW | Allwesta 510 | B |
| S355J2W | 1.8965 | WTSt 52-3 | E 36 WB 4 | WR 50 C | - | SMA 50 CP | Allwesta 510 F | B |
| S355K2G2W | 1.8967 | - | - | - | - | - | Allwesta 510 F 40 | B |
1) FK = Tensile strength class
Chemical composition in percent by weight [%] (Heat analysis)
| Grade | C | Si | Mn | P | S | N | Cr |
|---|---|---|---|---|---|---|---|
| max. | max. | max. | max. | ||||
| S235JOW1) | 0.13 | 0.40 | 0.20 - 0.60 | max. 0.035 | 0.035 | 0.0092) 3) | 0.40 - 0.80 |
| S235J2W1) | 0.13 | 0.40 | 0.20 - 0.60 | max. 0.035 | 0.030 | – 4) | 0.40 - 0.80 |
| S355JOWP1) | 0.12 | 0.75 | max. 1.00 | 0.06 - 0.15 | 0.035 | 0.0093) | 0.30 - 1.25 |
| S355J2WP1) | 0.12 | 0.75 | max. 1.00 | 0.06 - 0.15 | 0.030 | – 4) | 0.30 - 1.25 |
| S355JOW1)5) | 0.16 | 0.50 | 0.50 - 1.50 | max. 0.035 | 0.035 | 0.0092) 3) | 0.40 - 0.80 |
| S355J2W1)5) | 0.16 | 0.50 | 0.50 - 1.50 | max. 0.030 | 0.030 | – 4) | 0.40 - 0.80 |
| S355K2W1)5) | 0.16 | 0.50 | 0.50 - 1.50 | max. 0.030 | 0.030 | – 4) | 0.40 - 0.80 |
1) The steel contains a maximum of 0.25 to 0.55 % Cu and a maximum of 0.65 % Ni.
2) Exceeding the specified maximum value is permitted if the phosphorous content remains below the
maximum value by 0.005 % for each 0.001 % of nitrogen; however, the nitrogen content must not
exceed 0.012 % in the heat analysis.
3) The maximum nitrogen content shall not apply if the steel grades contain at least 0.020 % Altotal or
sufficient quantities of other nitrogen-fixing elements.
4) The steel grades contain at least one of the following elements: Altotal : ≥ 0.020 %, Nb: 0.015 - 0.060 %,
V: 0.02 - 0.12 %, Ti: 0.02 - 0.10 %. If a combination of these elements is present,
at least one of them is contained with the specified minimum content.
5) The steel may contain a maximum of 0.65 % Ni, 0.30 % Mo and 0.15 % Zr.
Mechanical properties1)
| Grade | Position of sample | Min. yield strength2) | Tensile strength2) | Min. total elongation2) | |||||
|---|---|---|---|---|---|---|---|---|---|
| MPa | MPa | % L0 = 80 mm |
% L0 = 5,65 √S0 | ||||||
| e ≤ 16 | e > 16 | e< 3 | e ≥ 3 | e ≤ 2 | 2 < e ≤ 2,5 | 2,5 < e ≤ 3 | e ≥ 3 | ||
| S235J0W | l/t | 235 | 225 | 360 - 510 | 360 - 510 | 19/17 | 20/18 | 21/19 | 26/24 |
| S235J2W | l/t | 235 | 225 | 360 - 510 | 360 - 510 | 19/17 | 20/18 | 21/19 | 26/24 |
| S355J0WP | l/t | 355 | - | 510 - 680 | 4703) - 6303) | 16/14 | 17/15 | 18/16 | 22/203) |
| S355J2WP | l/t | 355 | - | 510 - 680 | 4703) - 6303) | 16/14 | 17/15 | 18/16 | 22/203) |
| S355J0W | l/t | 355 | 345 | 510 - 680 | 490 - 630 | 16/14 | 17/15 | 18/16 | 22/20 |
| S355J2W | l/t | 3553) | 345 | 510 - 680 | 470 - 630 | 16/14 | 17/15 | 18/16 | 22/20 |
| S355K2W | l/t | 3553) | 345 | 510 - 680 | 470 - 630 | 16/14 | 17/15 | 18/16 | 22/20 |
of widths of ≥ 600 mm, transverse samples should be taken.
2) e = Nominal thickness in mm
3) S355J0WP and S355J2WP: e ≤ 12 mm
Notch impact energy in condition of delivery (minimum values obtained using Charpy-V samples)
| Grade | Temperature | Notch impact energy1) |
|---|---|---|
| °C | J | |
| S235J0W | 0 | 27 |
| S235J2W | -20 | 27 |
| S355J0WP | 0 | 27 |
| S355J2WP | -20 | 27 |
| S355J0W | 0 | 27 |
| S355J2W | -20 | 27 |
| S355K2W | -20 | 40 |
1) Average values of 3 samples; one individual value may fall short of the required minimum value by not
more than 30 %. The sample width shall equal the product thickness if the latter is between 5 - 10 mm,
the tests being performed using samples which are similar to Charpy-V samples. The values specified
in the table above are to be reduced proportionally to the sample width.
Formation of a protective coating
In the case of the phosphorous-alloyed steel grades Allwesta 510 P and Allwesta 510 FP (S355J0WP and S355J2WP), the barrier layer is also strengthened by alkaline copper phosphate.
Depending on the environmental conditions, the formation of this barrier layer takes approx. 1,5 - 3,5 years and prevents water, oxygen and sulphur dioxide from coming into contact with the surface of the steel. There is then no further corrosion.
The prerequisites for the formation of the protective coating are as follows:
· No permanent moisture
· Uniform run-off of rainwater
· Avoidance of small cracks
(capillary formation)
· Protective coating to protect against
condensation water on the inside
· Absence of chlorides
(seawater, near to the coast)
· Permanent fluctuation between moisture
and dryness
· Avoidance of electrochemical
local elements
As the protective coating forms, the colour changes from light brown to brown to brown-violet; the surface becomes dark brown / violet and grainy. The colour changes, depending on the incidence of light and the weather conditions.
Salzgitter Flachstahl should like to point out that, during the formation of the protective coating, specks may form as a result of the washout of rust; this should be taken into account in the design.
Welding
In general, pre-heating prior to welding or torch-cutting is not necessary. Only when external temperatures drop below -5 °C should the metal be pre-heated to approx. 150 °C.