### 1. What is SA 213 T11 material?
**SA 213 T11** is a **seamless ferritic alloy steel tube** for high-temperature service in boilers and superheaters. It is part of the ASTM A213/A213M standard and has a chemical composition of **1.25% chromium (Cr) and 0.5% molybdenum (Mo)**. It offers good creep strength and oxidation resistance up to ~595°C (1,100°F).
### 2. What is SA 213 material?
**SA 213** (officially **ASTM A213/A213M**) is an **American standard specification for seamless ferritic and austenitic steel boiler, superheater, and heat-exchanger tubes**. It covers multiple grades of corrosion-resistant, high-temperature alloys (e.g., T11, T22, TP304) used in pressurized systems.
### 3. What is T11 steel?
**T11 steel** is a **low-alloy steel grade** designated in ASTM A213. Its key composition is **1.25% Cr and 0.5% Mo**, with carbon ≤0.15%. It is heat-treated (normalized and tempered) to achieve optimal mechanical properties for high-temperature tubing applications.
### 4. What is the hardness of SA213 T11?
The typical hardness range for **SA213 T11** in the normalized and tempered condition is **150–200 Brinell Hardness (HB)**. Per ASTM A213, the maximum allowable hardness is **265 HB** to ensure weldability and prevent cracking.
### 5. What is the temperature range for SA213 T11?
- **Maximum Continuous Service**: **≤595°C (1,100°F)**
- **Intermittent Service**: Up to **650°C (1,200°F)**
- **Minimum Temperature**: **≥-29°C (-20°F)** (for stress-relieved welds)
**Critical Note**: Avoid prolonged exposure below **470°C (875°F)** due to **graphitization risk**, which can embrittle the steel.
