Can CrMo steel, the material chosen for hydrogenation reactors, operate over a long period at temperatures of 500–600°C?
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Dear experts, I would like to seek your advice regarding the material selection for hydrogenation reactors. 1) Our requirement is that the pressure can be at atmospheric levels; however, the temperature is relatively high, needing to operate at 500–600°C for more than 15 years. Moreover, the temperature often experiences significant fluctuations, such as dropping to room temperature before rising again. I checked the Nelson curve and wanted to choose 12Cr2Mo1R, but then I saw that it can develop temper brittleness when operating at temperatures between 450-600 degrees? ? It’s not known whether it can withstand a temperature of 600°C. 2) Is 12Cr2Mo1R magnetic? What’s the price? 3) For a hydrogenation unit operating at atmospheric pressure like mine, is it okay to use stainless steel? Type 316? 4) Some other materials, such as Hastelloy? Incoloy 800? Superalloys? Are their characteristics suitable? Why is it rarely used in hydrogenation units?
First, 12Cr2Mo1R develops temper brittleness when operated at temperatures between 450-600 for extended periods, but thanks to the improved manufacturing techniques available today, this phenomenon hardly occurs. The strength decreases significantly above 500°C, but it is still fine to operate at temperatures over 500°C for extended periods. If the internal pressure is not high at high temperatures, there’s no problem. If working conditions frequently change from normal temperature to high temperature and back again, fatigue must be taken into consideration. Second, 12Cr2Mo1R is magnetic, but only to a very slight extent, and this does not affect welding. You can inquire about the price from Wugang. Third, for a hydrogenation unit operating at atmospheric pressure like yours, if the pressure is not high and the wall thickness is not thick, stainless steel type 316 should also work fine. Fourth, there are other materials such as Hastelloy and Incoloy 800, which are other types of superalloys with excellent high-temperature strength; however, they are very expensive, with costs several times that of stainless steel. In hydrogenation units, in addition to strength and cost, other requirements such as resistance to hydrogen corrosion must also be taken into account.
Thank you for your answer! Regarding the fatigue issue you mentioned, are there any similar data available? Are there any standards?
It’s not entirely clear, but there are some doubts regarding whether 12Cr2Mo1R can be used at high temperatures of 600°C
If cost is completely ignored, what would be the most suitable choice?
If the operating temperature is around 500°C, the pressure is not high, below 1 MPa, and it involves a cycle of normal temperature – high temperature – normal temperature, then equipment used in coker towers in the oil refining industry can serve as a reference.
If the operating conditions are around 0.2 MPa and 600°C, it is recommended to use 304H.
If you need 304H or 316L stainless steel pipes, contact me at 13735933327