Questions about low-temperature impact energy
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For materials with requirements regarding low-temperature impact energy, when specifying this value, is it assumed that the low-temperature impact energy applies in a horizontal direction or a vertical direction? What are the directions for plates, pipes, and forgings respectively? I took a look at the steel pipe standards; they specify both longitudinal and transverse types. If I need to indicate this in the diagram, should I write longitudinal or transverse? If the default setting is horizontal, do I need to specify that it’s vertical when I write it as vertical?
It’s not necessary, as for the shell, Class A welding joints are considered; therefore, our country requires that impact tests be conducted in a transverse direction, which imposes higher requirements on the shell material. As for the pipes, since only Class B welding joints are used, impact tests are carried out in a longitudinal direction. If it were me, I would write: “The impact test method follows standard XXX, with a value not lower than XXXJ, ……………… and so on.”
According to their respective material standards, the mechanical property test sheets generally specify the sampling direction for impact tests. For example, GB6479-2013 specifies the sampling direction for impact tests.
Pressure vessels generally require lateral impact, and the technical specifications should specify the requirements for lateral impact.
Longitudinal sampling is feasible for small-diameter nozzles, while transverse sampling is difficult. The large diameter can be horizontal. Plate: GB713 is horizontal. Forgings vary depending on their shape – bowl, disc, ring – and forging standards specify the sampling direction for each type.