Scope of application and material properties of ASTM A213
In the fields of energy and chemical industry, tube is the core conduction carrier in the thermal system, and its performance directly affects the working efficiency of the equipment. ASTM A213 has become the authoritative standard for the manufacture of high-temperature seamless tubes through strict chemical composition control and heat treatment process. It is specifically aimed at the technical specifications of ferrite and austenite alloy steel seamless tubes. This standard points out the oxidation resistance and mechanical strength required in high temperature environments. Alloy irons such as T11 (1.25Cr-0.5Mo-Si) and T22 (2.25Cr-1Mo) improve their performance by adding alloying elements such as Cr, and can withstand temperatures as high as 650 degrees.
The function of ASTM A269 is the opposite, mainly for standards used in low temperature or corrosive environments. These two major standards form a complementary technology, work together, and are applied to multiple dimensions and multiple scenarios, and jointly establish a complete technical system.
Technical comparison between ASTM A213 and A269 standards
Material composition and mechanical properties
ASTM A213 can form a stable Cr₂O₃ oxide film in a high temperature environment due to the addition of chromium and molybdenum elements.
|
Performance Indicators |
ASTM A213 T22 |
ASTM A269 316L |
|
Maximum operating temperature |
650℃ |
450℃ |
|
Yield strength (25℃) |
415 MPa |
170 MPa |
|
Coefficient of thermal expansion |
12.4×10⁻⁶/℃ |
16.5×10⁻⁶/℃ |
Differences in heat treatment processes
ASTM A213 clearly stipulates that ferritic steel pipes must be subjected to normalizing + tempering treatment processes in order to optimize the material’s microstructure, improve creep resistance and mechanical properties, and enable it to work normally in extreme environments.
- Normalizing temperature: 890-950℃ (Ac₃ above 50℃)
- Tempering temperature: 730-790℃ (holding time ≥1h/25mm)
Through normalizing and tempering, this process can achieve a grain size of ASTM No.7 or above, and can be used normally under long-term high-temperature working conditions. In contrast, the ASTM A269 standard uses a solution treatment process for austenitic stainless steel welded pipes. The typical temperature of solution treatment is 1010-1120℃, which is conducive to improving the creep resistance of the material.
Collaborative application case with ASTM A269
In the waste heat recovery system of a chemical plant, engineers used two types of pipes, ASTM A213 Gr.T12 and A269 Gr.316L, to meet the different working conditions of the high-temperature channel and the cooling medium side. Due to the significant difference in the thermal expansion coefficients of T12 steel pipes and 316L pipes, thermal stress will be generated between the two materials. The expansion joint is set to reduce the fatigue damage of the pipes, and the heat exchange efficiency of the system is improved by 18%. This material exchange strategy fully reflects the engineering optimization brought by standard collaboration.
