The design temperature for austenitic stainless steel containers is -150 degrees Celsius; is it necessary to measure the ferrite content in the head?
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A device features an austenitic stainless steel container designed for temperatures of -150 degrees Celsius; the head is designed in accordance with the 2010 version standards. Is it necessary to indicate the ferrite content on the drawings? Furthermore, before the implementation of the new 150 standard, if the bolt diameter already exceeds the specifications for bolts with strain hardening as specified in 11th edition 150.2, can such bolts be used directly?
When austenitic stainless steel is used in low-temperature environments, it is indeed necessary to pay attention to the ferrite content, as an excessive amount of ferrite can lead to increased brittleness of the material at low temperatures. Normally, the design drawings should indicate whether a measurement of the ferrite content is required. As for whether the head needs to be marked, as you mentioned, it depends on the specific design requirements and safety standards. It is recommended to follow the currently valid relevant standards and specifications. Regarding bolts, if their diameter, as specified in the old standards, exceeds the range set by the new standards, it is best not to use them directly; instead, the choice of bolts should be re-evaluated to ensure compliance with the requirements of the new standards. It is reiterated that, to avoid safety hazards, it is recommended to select and use materials and components in accordance with the latest specifications and standards. .
The latest version of the standard for end caps, GB/T 25198-2023, came into effect on March 1, 2024, and it is necessary to comply with the requirements of this new standard.
Materials such as 304, 304L, and 321 must be tested, even though there are no requirements specified in the standards. There is basically no risk even with 316 accidents.
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It is necessary to comply with the new version of end caps and the GB150 standard; for cold-formed end caps, expansion joints need to be tested