What is S355 steel?
S355 is a low-alloy high-strength structural steel according to the European standard EN 10025. S stands for Structural, and 355 represents the minimum yield strength of 355 MPa (≤16mm).
What are some common S355 grades used in the automotive industry?
S355MC (EN 10149-2): Automotive-grade, thermomechanically rolled, with excellent cold forming/welding/stamping properties.
S355JR/J0/J2: General-purpose structural steel, commonly used in commercial vehicle frames/chassis.
3. What is the difference between S355 and Q355 (automotive material selection)?
S355: European standard, with stricter impurity (P/S) control, resulting in better low-temperature impact resistance.
Q355: Chinese standard, with similar composition and performance, but slightly lower cost.
→ S355 is used in export/European models, while Q355 is commonly used as a substitute in domestic commercial vehicles.
4. What are the differences between S355MC and regular S355?
S355MC: Dedicated for cold forming, with higher elongation (≈25%), and no cracking during deep drawing/bending.
Regular S355: Structural parts, high strength, but moderate formability.
→ MC is selected for complex automotive stamping parts, while JR/J0 is selected for chassis/beams.
5. What are the delivery conditions for S355 automotive sheet metal?
Hot-rolled/pickled (S355MC): Smooth surface, good paint adhesion.
Normalized (+N): Refines grain size, excellent low-temperature toughness (S355NL).