EN 10025-2 S275J0 Structural Steel Plate: Composition, Yield and Impact Data

Reading the S275J0 Designation

Under EN 10025-2, which gives the technical delivery conditions for non-alloy structural steels, the designation S275J0 is decoded in three parts. The letter S identifies structural steel, 275 is the minimum yield strength in MPa for the thinnest thickness range covered, and J0 identifies the impact quality group, which requires a Charpy V-notch energy of 27 J at 0 C. EN 10025-2:2019 is the current edition of the part that applies to flat and long products supplied in the as-rolled, normalised or normalising-rolled condition.

Chemical Composition

Table 1 gives the heat analysis limits for S275J0. The restricted phosphorus and sulfur limits are what separate J0 from the JR quality group, and they also improve through-thickness behaviour and weld metal quality.

Yield Strength and Thickness

Yield strength falls as plate thickness rises, because the amount of deformation the rolling schedule can impose on the core of a thick plate is limited. Table 2 gives the minimum yield strength of S275J0 across the main thickness steps, together with the tensile strength range that applies.

Plate is commonly rolled in the range 4 mm to 400 mm thick, 1000 mm to 4000 mm wide and 4000 mm to 12000 mm long, and each thickness range must be quoted in the order because the mechanical values follow the thickness rather than the grade alone.

Impact Toughness and Quality Groups

The J0 suffix certifies a minimum Charpy V-notch energy of 27 J at 0 C on longitudinal test pieces. The other quality groups in EN 10025-2 use the same 27 J energy at different test temperatures: JR is tested at 20 C, J2 at minus 20 C, and K2 at minus 20 C with a tighter energy requirement. Impact testing is carried out on a frequency basis defined in the standard, and the test temperature must sit in the purchase order, not only the grade name, because J0 and JR are frequently confused during ordering.

Carbon Equivalent and Weldability

Weldability is controlled by the maximum carbon equivalent value, which is calculated from the heat analysis using the formula given in the standard. Table 3 lists the limits for S275J0.

Because carbon is held to 0.18% max, S275J0 can be welded to other weldable steels with conventional processes, and preheat is normally selected from the welding procedure and the actual carbon equivalent on the mill certificate rather than from the grade name alone. The steel is delivered with a specific surface condition and marking to EN 10025-1, and plates are supplied with inspection documents to EN 10204 3.1 on request.

Frequently Asked Questions

Q: What does J0 mean in S275J0?
A: It is the impact quality group, which requires 27 J minimum Charpy V-notch energy at 0 C.

Q: What is the minimum yield strength of EN 10025-2 S275J0 plate?
A: 275 MPa for thickness up to 16 mm, falling to 265 MPa for 16 to 40 mm and 255 MPa for 40 to 63 mm.

Q: What is the maximum carbon content of S275J0?
A: 0.18% by heat analysis for product thickness up to 40 mm.

Q: Is S275J0 a high-strength low-alloy steel?
A: No. It is a non-alloy structural steel; designers who need extra strength with micro-alloying move to S355 grades or to a separate high-strength specification.

Q: What thickness of S275J0 plate is available?
A: Plate is regularly produced from 4 mm to 400 mm thick, with width 1000 mm to 4000 mm and length 4000 mm to 12000 mm.

Q: What documentation is supplied with S275J0 plate?
A: An inspection certificate to EN 10204 3.1 stating heat analysis, tensile results, carbon equivalent and, where applicable, impact test results.