Calculations regarding the steel plates lining the tower section
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The reactor section of one of our towers (H2500mm, ID1800) is corroded; the material used is 16MnR with a thickness of 20mm. Now, steel plates made of 317L material with a thickness of 4 mm are to be used for the internal lining. According to the design, these lining plates are to be divided into plates that are 500 mm wide and 1400 mm long, and then welded together; the plates are supplied in rolls with an outer diameter of 1800 mm. The operating temperature here is approximately 86.6 degrees. 14mm plug welding holes are provided on the board. Due to the differences in linear expansion coefficients among different materials caused by temperature changes, it is now necessary to determine whether the weld strength meets the requirements I wonder if anyone expert can help! Thank you
The last edit to this post was made by jizhanwei22 on 2017-5-24 at 16:32. It seems that there is no need to calculate the strength of the welds, but visual inspection, flaw detection, and plug welding test pieces are required (mechanical property tests, namely 3 tensile tests and 2 shear tests for the plug welded joints)； 2 tensile tests and 2 bending tests on the clad welds), corrosion tests on the materials, and inspection using compressed air to check for leaks in the plug welds and clad welds......
Do these two materials have a high coefficient of linear expansion?
It seems there’s a pretty big difference – one is around 10, and the other is around 15; the unit is 10-6
If one doesn’t want to do the calculations themselves and feels that the expansion amount is too small, then a composite panel should be used.
The idea is as follows: with two different materials, the main concern is that differing linear expansion coefficients may lead to cracking due to thermal expansion and contraction. So, it is necessary to calculate the force generated by the linear expansion just now; this force acting on the solder joint is a shear force. By then calculating the shear strength, everything will be clear
The operating temperature is 86.6°C; calculating the expansion at room temperature (20°C) shows that it can be considered negligible.
The equipment suitable for seam welding has certain requirements, with limits on temperature and pressure. For details, see TCED41002-2000; the revised version (2012 edition) removes the chapter on plug-welded stainless steel.
With a thickness of 20 mm, it indicates that the operating pressure of the equipment is likely not too low, or perhaps the tower is quite tall. The lining must be difficult to work with, right? Using a different type of composite panel should be better than using an inner lining. Can fiberglass reinforcement also be used inside?