S9074-AR-GIB-010/278
Table VI-Post Heat Requirements for Welded ferrous alloys - Continued 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 Thermal stress relief is required. No exceptions. All attachments or parts welded thereto shall be stressed relieved.
Holding Tempera ture *F 2/, 3/
Material Group Number
Material Identifica tion 1/
Machinery class M 1/
Piping Class P
1250- 1375
Thermal stress relief mandatory should S-4 materials be used to fabricate class M machinery parts.
Except as specified in footnotes 5 and 7, thermal stress relief is required when any one of the following apply: (a) carbon content is over 0.15 percent, (b) wall thickness is in excess of 5/8 inch, (c) pipe size exceeds 4 inches maximum nominal outside diameter, (d) preheat and interpass temperature was below 250*F. Except as specified in footnotes 5 and 7, thermal stress relief is required when any one of the following apply: (a) carbon content is over 0.15 percent, (b) chromium content is over 2.75 percent, (c) wall thickness is in excess 5/8 inch, (d) pipe size exceeds 4 inches maximum nominal outside diameter, (e) preheat or interpass temperature was below 300*F.
6/, 7/ S-4 Alloy steel (Cr content 3/4 - 2 percent, total alloy
content 2 - 3/4 percent maximum)
1350- 1400
6/, 7/ S-5 Alloy steel (total alloy content 10 percent maximum)
Thermal stress relief mandatory should S-5 be used to fabricate class M machinery parts.
Thermal stress relief is required. No exceptions. All attachments or parts welded thereto shall be stressed relieved.
Original 64
Made with FlippingBook - Share PDF online