S9074-AR-GIB-010/278
Table VI-Post Heat Requirements for Welded ferrous alloys
Applicable supplementary provisions and exceptions
Pressure vessels, turbines classes A-F, A-LT, A-1, A-2, A-3, A-4, T-1, and T-2
Material Group Number
Material Identifica tion 1/ Low alloy quenched & tempered steel
Holding Temperatu re *F 2/, 3/
Piping Class P
Machinery class M 1/
Stress relief of S-11 materials is prohibited unless specifically approved by NAVSEA. See 6.5.
S-11
-
1.) Materials used in fabrication of machinery components and not covered in this table shall be stress relieved in accordance with the conditions established by approved welding procedure qualification tests. 2.) For quenched and tempered or normalized and tempered alloys, stress relief temperatures shall not exceed base metal tempering temperatures and, in general, should be approximately 50*F below tempering temperature.
3.) Minimum holding time at temperature shall be 1 hour per inch of thickness. For thicknesses less than 1 inch, the holding time shall be proportional to the thickness but not less than 30 minutes.
4.) When it is impractical to post-weld heat treat at temperatures specified in Table VI, it is permissible to use lower temperatures for longer periods of time as follows:
Minimum holding time at decrease temperature, hours per inch of thickness
Temperature decrease below specified temperature *F 50
2 3 5 10
100 150 200
5.) Where carbon content of pipe or fitting exceeds 0.15 percent but is not greater than 0.20 percent, stress relief is not require for socket welds 2 inches nps and under, provided welding is done with the low carbon type electrodes (80XX-B2L for 1-1/4 Cr-1/2 Mo; and 90XX-B3L for 2-1/4 Cr-1 Mo).
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