**1. What material is S235JR pipe made of?**
S235JR pipe is made of **non-alloy structural steel** as per the European standard EN 10025-2. It has a minimum yield strength of 235 MPa. The "JR" designation indicates it is impact tested at **20°C** with a minimum energy absorption of **27 Joules**. It is commonly used in general construction due to its good weldability and formability.
**2. What are the properties of S235JRH steel?**
S235JRH is a **cold-formed welded hollow structural steel** (EN 10219-1). Its properties include:
- Minimum yield strength: **235 MPa**
- Good **weldability** and **ductility**
- Impact toughness tested at **0°C** (the "H" denotes hollow sections, not temperature rating).
- Low carbon content (≤0.17%) and controlled sulfur/phosphorus levels for enhanced durability.
**3. What are the three types of steel pipes?**
The three primary types based on manufacturing methods are:
- **Seamless Pipes**: Made by extruding solid billets, used for high-pressure applications.
- **Welded Pipes**: Formed by rolling steel coils and welding seams (subtypes include ERW, LSAW, and SSAW).
- **Galvanized Pipes**: Coated with zinc to resist corrosion, commonly used in plumbing and outdoor structures.
**4. What is the standard S355 pipe?**
S355 pipes comply with **EN 10210-1 (hot-finished)** or **EN 10219-1 (cold-formed)** standards for structural hollow sections. Key features include:
- Minimum yield strength: **355 MPa**
- Enhanced toughness and weldability.
- Subgrades like S355J2H or S355K2H, indicating impact test temperatures (e.g., -20°C for J2).
**5. What is S355 grade steel?**
S355 is a **high-strength low-alloy (HSLA) structural steel** with a minimum yield strength of 355 MPa. It offers:
- Superior mechanical properties compared to S235.
- Improved toughness at low temperatures (subgrades like S355J2, S355K2).
- Applications in heavy-load structures (bridges, cranes) and components requiring high stress resistance.
- Composition includes controlled carbon, manganese, and microalloying elements (e.g., niobium, vanadium) for strength.
