What is the minimum operating temperature for Q345B?
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What is the minimum operating temperature for Q345B GB6479-2013? Can the temperature used for impact testing be considered as the minimum operating temperature for this material? The impact test temperature for Q345B is 20°C; considering that temperature to be 20°C seems a bit too high.
For steel pipes made of the standard Q345B material, the minimum operating temperature is 20°C
The minimum operating temperature specified in the national standards for metal pipes should be referred to in the provisions of GB 20801. In principle, carbon steel can be used at -20°C, and Q345B can also be used at -20°C℃
It is the operating temperature that matters; for pressure pipes, impact tests must be conducted at temperatures equal to or lower than this value. The impact test temperature for Q345b is only 20 degrees, and at even lower medium temperatures, the inspection of steel pipes may not meet the required test standards. 20801 also contains 16Mn; its minimum operating temperature is -20 degrees Celsius. This grade likely refers to Q345D. Using Q345b at around 0 degrees is definitely fine; from this standard perspective, however, the impact test results for Q345b are no longer sufficient to verify performance under conditions of around 0°C.
The minimum operating temperature for steel pipes made of the standard Q345B material is 20°C.
According to GB150 5.1.5, it is -20 degrees