What is en 10219 S355J2H equivalent to?
1. Basic Benchmarking Relationship
The closest domestic grade:
S355J2H corresponds to domestic Q345D (GB/T 1591), and the two are highly matched in yield strength (≥355MPa) and low-temperature impact toughness (-20℃ impact energy ≥27J).
Note: The carbon equivalent and some elements (such as nitrogen content) of Q345D may be slightly different from S355J2H.
2. Comparison of Chemical Composition
| Composition | S355J2H(EN10219) | Q345D(GB/T 1591) |
|---|---|---|
| C | ≤0.22% | ≤0.18% |
| Mn | ≤1.60% | ≤1.70% |
| P | ≤0.025% | ≤0.025% |
| S | ≤0.025% | ≤0.020% |
| N | ≤0.009% |
Note: The silicon (Si) content of Q345D is ≤0.55%, which is consistent with S355J2H; the micro-alloy elements such as niobium (Nb) and vanadium (V) of S355J2H need to be matched through process adjustment.
3. Mechanical properties and process differences
Mechanical properties:
Yield strength: The strength of S355J2H decreases with increasing thickness (such as ≥355MPa when the wall thickness is ≤16mm, and ≥345MPa when 16-40mm), which is consistent with the strength distribution law of Q345D.
Low temperature impact: Both require -20℃ impact energy ≥27J to meet the requirements of conventional low temperature environment.
Process requirements:
S355J2H needs to optimize the grain through normalizing rolling (N) process, while Q345D usually adopts controlled rolling and cooling (TMCP) process, and the heat treatment process needs to be adjusted to ensure the uniformity of the structure.
4. Application Recommendations
General substitution: Q345D can replace S355J2H for structural parts in normal temperature or -20℃ environment such as building frames and bridge supports; Severe working conditions: When welding or low-temperature impact-sensitive scenes are involved, it is necessary to verify the actual impact energy of Q345D (recommended ≥34J) and optimize the welding process.
Summary
EN10219 S355J2H is closest to domestic Q345D in mechanical properties and low-temperature toughness, but attention should be paid to chemical composition differences (such as carbon and nitrogen content) and process adjustments (such as normalizing treatment). It is recommended to verify the material properties in combination with specific working conditions when actually replacing.
