Do containers that have undergone post-weld heat treatment need to be made into welding test pieces?
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Condition for preparing product welding specimens under new code requirement 4.3.1, clause (3): Steel pressure vessels that require heat treatment to improve or restore their mechanical properties. Does post-weld heat treatment fall under this category?
Of course. Clause 9.1.1.1 d of GB150-2011 also contains the same provision.
Not all post-weld heat treatments require test pieces. Generally, heat treatments are divided into four types: stress-relief heat treatment after welding, heat treatment to restore mechanical properties, heat treatment to improve mechanical properties, and hydrogen removal treatment. Among them, stress relief treatment and dehydrogenation do not fall under those two categories specified in the tolerance standards, and test plates are not required.
Heat treatment used to improve or restore the mechanical properties of materials is generally not post-weld heat treatment
If it is only post-weld heat treatment to eliminate welding residual stresses, there is no need to prepare test pieces.
Unify the views above: stress-relief heat treatment can eliminate the need for welded test pieces