The series of normalized rolled fine-grain structural steels is characterized by a minimum yield strength of 275 - 355 MPa, by good weldability and high resistance to brittle fracture. These grades are used above all for manufacturing highly stressed welded structures in the construction of heavy machinery, bridges and steel structures.
The special grades S...NL are available for application temperatures below -20 °C.
The user of these steel grades must make sure that his calculation, design and processing methods are appropriate for the material. The welding technique used must be suitable for the intended application and comply with the state-of-the-art.
The steel grades of this series offer good cold-forming and hot-forming properties without negatively affecting the material properties. These steel grades are therefore also suitable for cold-bordering and cold-flanging as well as for cold-bending and folding.
2.0* nominal thickness, for bending axis transverse to rolling direction
2.5* nominal thickness for bending axis parallel to rolling direction
With cold-forming above 5% or hot-forming outside of the temperature range or 1.050 - 850 °C as well as after excess times, the plates should be subsequently normalized at 880 - 930 °C. The holding time is approx. 0.5 minutes per millimeter of plate thickness.
We would like to draw the user's attention to Stahl-Eisen-Werkstoffblatt’ (Iron and steel material sheet) 088.
|Europe||Material no.||D||F||I||GB||E||USA||Salzgitter Flachstahl||FK1)|
|EN 10025-3||DIN 17102||NFA 36-201||UNI 7382||BS 4360||UNE 36081||ASTM|
|S275N||1.0490||StE 285||-||Fe E 285 KGN||43 E||AE 285 KG||-||SBS 275||A|
|S275NL||1.0491||TStE 285||-||Fe E 285 KTN||43 EE||AE 285 KT||A 633 Gr. A||SBS 275 K||A|
|S355N||1.0545||StE 355||E 355 R||Fe E 355 KGN||50 E||AE 355 KG||-||SBS 355||B|
|S355NL||1.0546||TStE 355||E 355 FP||Fe E 355 KTN||50 EE||AE 355 KT||A 633 Gr.||SBS 355 K||B|
|S275N||0.18||0.40||0.50 - 1.50||0.030||0.025||0.015||0.02||0.55||0.30||0.05||0.40|
|S275NL||0.16||0.40||0.50 - 1.50||0.025||0.020||0.015||0.02||0.55||0.30||0.05||0.40|
|S355N||0.20||0.50||0.90 - 1.65||0.030||0.025||0.015||0.02||0.55||0.50||0.12||0.43|
|S355NL||0.18||0.50||0.90 - 1.65||0.025||0.020||0.015||0.02||0.55||0.50||0.12||0.43|
|Grade||Min. yield strength2)||Tensile strength||Min. total elongation [%]2)|
|MPa||MPa||LO = 5,65 √SO|
|e ≤ 16||e > 16||e ≥ 3|
|S275N||275||265||370 - 510||24|
|S275NL||275||265||370 - 510||24|
|S355N||355||345||470 - 630||22|
|S355NL||355||345||470 - 630||22|
|Grade||Position of samples||Minimum value of both impact energy1) [J] at a test temperature of [°C]|
The fine-grain structural steel grades of this series can be perfectly welded both manually and using automatic equipment by means of all known welding processes. However, the quality of the weld joint depends on the welding process, the welding conditions and the selection of the correct filter metals.
The welding wires and electrodes approved in this strength category must be used as filter metals. Basic coated electrodes are recommended for manual welding.
In general, pre-heating prior to welding or torch -cutting is not necessary for the steel grades S275N and S275NL. At outside temperatures below +5 °C, plates of all other grades of this series should be preheated to 150 °C (see also Stahl-Eisen- Werkstoffblatt [iron and steel material sheet] 088).
Subsequent normalizing or stress relieve annealing is required only if called in the regulations or if operating and manufacturing conditions make a reduction of the residual welding stresses appear useful. With stress relieve annealing at 530 - 580 °C, the holding time should be 2 minutes per millimeter of plate thickness, not fall short of 30 minutes and not significantly exceed 60 minutes.
Excessively high annealing temperatures or excessively long annealing times bear the risk of reducing the strength values to below the condition of delivery.
In addition to this, the guidelines for processing these steel grades according to Stahl-Eisen-Werkstoffblatt (Iron and steel material sheet) 088 must be observed.
Condition of delivery, scope of inspections and certificate
inspections and certificate The provisions of EN 10025-3 shall apply for delivery and inspection. The products are delivered normalized rolled.
Certificates according to DIN EN 10204 can be supplied as follows: IT, DUN, FAX, e-mail, paper.