What is the difference between S275JR and S355JR steel

What is the difference between S275JR and S355JR steel

S275JR and S355JR steel are low alloy steel materials under standard EN10025-2. In the steel grades, “S” means structure steel, the number “275” and “355” means the Min. yield strength of S275JR and S355JR steel are 275Mpa and 355Mpa respectively. “JR” indicates the steel needs +20℃ impact test.

What is the difference between S275JR and S355JR steel?
Chemical composition difference between S275JR and S355JR steel: %

Grade C  (t≤16mm) Si Mn P S Cu N
S275JR 0.24 max - 1.60 max 0.045 max 0.045 max 0.60 max 0.014 max
S355JR 0.27 max 0.6 1.70 max 0.045 max 0.045 max 0.60 max 0.014 max

Mechanical properties difference between S275JR and S355JR steel:

Grade Yield strength ReH/(N/mm2) (t≤16mm) min Tensile strength Rm/(N/mm2) (3mm≤t≤16mm) Elongation A/%(3mm≤t≤40mm) min Charpy V test
Temperature/℃ Impact energy (Longitudinal)/J min
S275JR 275 410-560 23 20 27
S355JR 355 470-630 22 20 27

The chemical composition difference between S275JR and S355JR steel is not outstanding other than Carbon content. The carbon content of S355JR steel is higher than S275JR steel. Accordingly, the S355JR steel strength is higher than S275JR steel strength.