What is the difference between S355JR and S275JR?
I. Chemical Composition
The chemical compositions of S275JR and S355JR differ slightly. S275JR has a lower carbon content, approximately 0.16%-0.22%, while S355JR has a higher carbon content, approximately 0.20%-0.26%. Furthermore, the manganese content also differs between the two grades: S275JR contains 1.3%-1.6% manganese, while S355JR contains 1.4%-1.8%.
Chemical Composition Comparison
| Element | S355JR (%) | S275JR (%) |
|---|---|---|
| Carbon (C) | ≤0.20 | ≤0.22 |
| Silicon (Si) | ≤0.55 | ≤0.55 |
| Manganese (Mn) | ≤1.60 | ≤1.60 |
| Phosphorus (P) | ≤0.035 | ≤0.035 |
| Sulfur (S) | ≤0.035 | ≤0.035 |
II. Mechanical Properties
Due to the differences in chemical composition, the mechanical properties of S275JR and S355JR also differ. S275JR has a yield strength of 275 MPa, a tensile strength of 350-490 MPa, and an elongation of 22%; while S355JR has a yield strength of 355 MPa, a tensile strength of 470-630 MPa, and an elongation of 21-22%. It can be seen that S355JR has higher strength than S275JR, but their elongation is similar.
Mechanical Properties Comparison
| Property | S355JR (MPa) | S275JR (MPa) |
|---|---|---|
| Yield Strength (Re) | ≥355 | ≥275 |
| Tensile Strength (Rm) | 470-630 | 360-510 |
| Elongation (A) | ≥22% | ≥23% |
III. Applications
Due to the different mechanical properties of S275JR and S355JR, their application areas also differ. S275JR is mainly used in general building structures and machinery manufacturing, such as bridges, high-rise buildings, and factories. S355JR, due to its higher strength, is mainly used in structures bearing greater loads, such as large ships and heavy machinery.
Mechanical Performance Comparison
| Property | S355JR | S275JR |
|---|---|---|
| Impact Toughness (KV) | ≥27J (0℃) | ≥27J (0℃) |
| Hardness (HBW) | ≤187 | ≤187 |
S355JR and S275JR RHS Tube factory
