Pressure 2Mpa. Can 20 steel seamless tubes be used at a temperature of -13°C?
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As title suggests, the pressure is 2 Mpa. Can 20 steel seamless tubes be used at a temperature of -13°C? Thank you
No, low-temperature grade 20 steel is not suitable.
GB 20801 specifies that the minimum operating temperature for 20 seamless steel pipes is -20; since the current temperature is already at -13, it’s better to use a different material.
The material requirements of the new GB150.2-2011 specify the usage rules for steel pipes of various grades listed in GB 6479 as follows: a) The sulfur content in the steel shall not exceed 0.020%； b) The heat exchange tubes should be made of cold-drawn or cold-rolled steel pipes, with the dimensional accuracy of these pipes requiring high precision. c) 20 and 16Mn steel pipes with an outer diameter of not less than 70 mm and a wall thickness of not less than 6.5 mm shall undergo impact tests at 0°C and -20°C respectively; the average impact energy of 3 longitudinal standard specimens shall be not less than 31 J and 34 J respectively. The minimum value for 1 specimen, as well as the impact energy value for small-sized specimens, shall comply with the provisions of 3.8.2. The lower operating temperature limits for 20 and 16Mn steel pipes are 0°C and -20°C respectively.
It is possible to calculate whether it is a low-temperature and low-stress condition; if 20 steel meets such conditions, it can be used.
This post was last edited by tjsyhx@163.com on 2016-5-11 23:06. The stress level is not very high, but considering low temperatures, 20# steel is not the preferred material; 10#, Q345D, and Q345E are recommended. These materials can generally be used for production. If the amount of this type of pipe used is not large, and the low temperatures occur only occasionally, then from an economic and practical standpoint, 20 steel can also be considered·····