Low-temperature resistant materials
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A material that is widely used for withstanding low temperatures these days is an aluminum alloy; stainless steel is also used as such a material. My question is: what type of stainless steel can withstand temperatures as low as -190°C? What is the commonly used aluminum alloy material? (Note: This question arose during studies on low-temperature processes such as liquid nitrogen washing and air separation.)
Austenitic stainless steel will do, such as 304 and the like.
Reply to 2# SPECIALIST: 304 stainless steel is resistant to high temperatures, but can it be used at low temperatures of -190°C? Could there be any hidden risks?
You can look up the parameters related to the use of 304; that’s possible
It seems that 304 can only withstand temperatures of -180°C. I only know that some manufacturers use this material in their cryopumps, so I’m not entirely sure whether it can be used in deep-freezing conditions below -190°C. . .
It is definitely possible to reach -196 degrees; of course, there are certain requirements regarding the properties of the fluid – for example, the medium should be liquid nitrogen or liquid argon obtained from air separation. You might want to check the material of the pipes located near the cryostat
If it is a pressure vessel, follow Appendix C of GB150. For austenitic stainless steels, the requirements for C1.4 are as follows: C1.4 chromium-nickel austenitic stainless steel low-temperature vessels need not comply with the provisions of this appendix when the design temperature is equal to or higher than -196°C and the following requirements are met. a) The base material shall be chromium-nickel austenitic stainless steel with a carbon content of less than or equal to 0.10%, in compliance with this standard; b) The welding materials and procedures shall meet the requirements of JB/T 4709; c) When the design temperature is below -100°C, low-temperature Charpy (V-notch) impact tests on the weld metal shall be conducted in accordance with JB4708, and the requirements of C2.1.7 shall be met
Generally, in processes such as air separation, conditions of low temperature and normal pressure prevail, so there is no need to follow Appendix C of GB150; in other words, it is a situation of \"low temperature and low stress\".
Reply to 8# cgp188: You’re wrong. Air separation is not ordinary low-temperature technology; the operating temperatures of the nitrogen and oxygen distillation columns in air separation units are generally around 190°C, which classifies them as cryogenic equipment. Moreover, the hyperbaric oxygen heat exchanger in the vacuum section is subjected to a maximum pressure of 8.65 MPa and a temperature of -172.5°C; it is a cryogenic medium-pressure device!
Ordinary stainless steel cannot meet such requirements; materials such as SA203D, E, 16MnR, and 16MnDR are not suitable either. Only low-temperature resistant materials like 304, 304L, and 321 can be used in these applications.
The low-temperature material LC9 can be used.