1. What is S275JR Steel?
Answer: S275JR is a non-alloy structural steel grade according to the European standard EN 10025-2. The "S" stands for "Structural Steel," "275" indicates the minimum yield strength of 275 MPa at thicknesses ≤ 16mm, and "JR" signifies an impact energy of 27 J at room temperature (+20°C).
2. What are the key mechanical properties of S275JR steel pipe?
Answer: The key mechanical properties vary with thickness. For sections ≤ 16mm:
Yield Strength (ReH): Min. 275 MPa
Tensile Strength (Rm): 410 - 560 MPa
Minimum Elongation: Varies, but typically around 23% (depends on the specimen and thickness).
3. What is the chemical composition of S275JR?
Answer: The composition is capped to ensure weldability and mechanical properties. Maximum values for non-alloyed quality (by weight %) are typically:
Carbon (C): ≤ 0.21%
Manganese (Mn): ≤ 1.50%
Silicon (Si): ≤ 0.55%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.035%
4. Is S275JR steel pipe weldable?
Answer: Yes, S275JR is generally considered to have good weldability due to its relatively low Carbon Equivalent (CEV). Common welding methods like MMA (SMAW), MIG/MAG (GMAW), and TIG (GTAW) can be used without pre-heating for most standard thicknesses, though specific procedures should always be followed.
5. What is the equivalent of S275JR in other standards?
Answer: A common and very close equivalent is ASTM A36 carbon steel. However, it's important to note that while the mechanical properties are similar, the chemical compositions and testing requirements differ between the EN and ASTM standards. Another rough equivalent is JIS G3101 SS400.
