关于预热AWS里的规定,仅供参考:
XI6.2.4 Minimum Preheat Levels and Interpass.
Table XI-2 gives the minimum preheat and interpass
temperatures that shall be used. Table XI-2 gives three
levels of restraint. The restraint level to be used shall be
determined in conformance with XI6.2.5.
XI6.2.5 Restraint. The classification of types of
welds at various restraint levels should be determined on
the basis of experience, engi neering judgment, research,
or calculation.
Three levels of restraint have been provided:
(1) Low Restraint. This level describes common fil-let and groove welded joints in which a reasonable free-dom of movement of members exists.
(2) Medium Restraint. This level describes fillet and
groove welded joints in which, because of members
being already attached to st ructural work, a reduced free-dom of movement exists.
(3) High Restraint. This level describes welds in
which there is almost no freedom of movement for mem-bers joined (such as repair welds, especially in thick
material
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