Lower temperature limit for ASME materials
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Help: Is there anyone familiar with ASME materials? How can I find out the minimum operating temperature? Such as SA-516 Gr.70
1. ASME does not specify a fixed minimum service temperature for any particular material; this requires comprehensive consideration, as stated in point 2. 2. MDMT is related to materials, condition of delivery, heat treatment, stress levels, etc.; consult the impact test exemption curve. 3. The impact value can be found in UG84.
The minimum operating temperature for ASME materials is related to the impact energy permitted at that temperature; it needs to be determined based on the lowest metal operating temperature specified by the designer for the container, and then the corresponding temperature and impact energy values for the materials in ASME Volume II are consulted to make the decision
Okay, I’m aware of this. For example, in the case of SA-516 Gr.70 plates with a thickness of 20 mm that have not been normalized, the minimum design temperature for the equipment is 50°C. By referring to the impact test exemption curve in UCS-66M, the minimum design metal temperature for a 20 mm thick plate is -9°C; therefore, an impact test is required； But I wonder if there is any available information on at what temperatures carbon steel becomes unusable due to low temperatures, as low-temperature cracking can occur
Refer to the appendix of sa-20 for the recommended minimum impact temperature; follow that value.
The ASME VIII-Ⅰ code does not have such a mandatory requirement; as long as the impact test has been conducted, it can be continued to be used.
Refer to Appendix Table 2.15 in A20: the minimum operating temperature for SA516Gr70 is -46°C for thicknesses ≤ 25 mm, -40°C for 26–50 mm, -35°C for 51–75 mm, and -29°C for 76–125 mm. This is provided that the steel plate has been normalized and subjected to low-temperature impact tests at the corresponding temperatures, with an impact energy of not less than 20 J on average and 16 J for individual tests. Wugang Panglong 13137747779