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ASME B31.3-2016
<br /> Table 331.1.1 Postweld Heat Treatment (16)
<br /> Minimum Holding Time at Temperature for
<br /> P-No.and Group No. Holding Temperature Range,
<br /> Control Thickness [Note(2)]
<br /> (BPV Code Section IX, QW/QB-420) °C( F) [Note(1)] Up to 50 mm (2 in.) Over 50 mm (2 in.)
<br /> P-No. 1, Group Nos. 1-3 595 to 650 (1,100 to 1,200) 1 h/25 mm (1 hr/in.); 2 hr plus 15 min for each
<br /> P-No. 3, Group Nos. 1 and 2 595 to 650 (1,100 to 1,200) 15 min min. additional 25 mm (in.)
<br /> P-No. 4, Group Nos. 1 and 2 650 to 705 (1,200 to 1,300) over 50 mm (2 in.)
<br /> P-No. 5A, Group No. 1 675 to 760 (1,250 to 1,400)
<br /> P-No. 513, Group No. 1 675 to 760 (1,250 to 1,400)
<br /> P-No. 6, Group Nos. 1-3 760 to 800 (1,400 to 1,475)
<br /> P-No. 7, Group Nos. 1 and 2 [Note (3)] 730 to 775 (1,350 to 1,425)
<br /> P-No. 8, Group Nos. 1-4 PWHT not required unless required by WPS
<br /> P-No. 9A, Group No. 1 595 to 650 (1,100 to 1,200)
<br /> P-No. 913, Group No. 1 595 to 650 (1,100 to 1,200)
<br /> P-No. 10H, Group No. 1 PWHT not required unless required by
<br /> WPS. If done, see Note (4).
<br /> P-No. 10I, Group No. 1 [Note (3)] 730 to 815 (1,350 to 1,500)
<br /> P-No. 11A 550 to 585 (1,025 to 1,085) [Note (5)]
<br /> P-No. 15E, Group No. 1 705 to 775 (1,300 to 1,425) 1 h/25 mm (1 hr/in.); 1 h/25 mm (1 hr/in.) up
<br /> [Notes (6) and (7)] 30 min min. to 125 mm (5 in.) plus
<br /> 15 min for each addi-
<br /> tional 25 mm (in.) over
<br /> 125 mm (5 in.)
<br /> P-No. 62 540 to 595 (1,000 to 1,100) ... See Note (8)
<br /> All other materials PWHT as required by WPS In accordance with WPS In accordance with WPS
<br /> GENERAL NOTE: The exemptions for mandatory PWHT are defined in Table 331.1.3.
<br /> NOTES:
<br /> (1) The holding temperature range is further defined in para. 331.1.6(c) and Table 331.1.2.
<br /> (2) The control thickness is defined in para. 331.1.3.
<br /> (3) Cooling rate shall not be greater than 55°C (100°0 per hour in the range above 650°C (1,200°F), after which the cooling rate shall be
<br /> sufficiently rapid to prevent embrittlement.
<br /> (4) If PWHT is performed after welding, it shall be within the following temperature ranges for the specific alloy,followed by rapid cooling:
<br /> Alloys S31803 and S32205 - 1 020°C to 1 100°C (1,870°F to 2,010°0
<br /> Alloy S32550- 1 040°C to 1 120°C (1,900°F to 2,050°0
<br /> Alloy S32750- 1 025°C to 1 125°C(1,880°F to 2,060°F)
<br /> All others - 980°C to 1 040°C (1,800°F to 1,900°0.
<br /> (5) Cooling rate shall be>165°C (300°F)/h to 315°C (600°F)/h.
<br /> (6) The minimum PWHT holding temperature may be 675°C (1,250°0 for nominal material thicknesses [see para. 331.1.3(c)]
<br /> 513 mm (112 in.).
<br /> (7) The Ni + Mn content of the filler metal shall not exceed 1.2% unless specified by the designer, in which case the maximum tempera-
<br /> ture to be reached during PWHT shall be the Al (lower transformation or lower critical temperature) of the filler metal, as determined by
<br /> analysis and calculation or by test, but not exceeding 800°C (1,470°F). If the 800°C (1,470°0 limit was not exceeded but the Al of the
<br /> filler metal was exceeded or if the composition of the filler metal is unknown,the weld must be removed and replaced. It shall then be
<br /> rewelded with compliant filler metal and subjected to a compliant PWHT. If the 800°C (1,470°0 limit was exceeded,the weld and the
<br /> entire area affected by the PWHT will be removed and, if reused, shall be renormalized and tempered prior to reinstallation.
<br /> (8) Heat treat within 14 days after welding. Hold time shall be increased by 1.2 h for each 25 mm (1 in.) over 25 mm (1 in.) thickness.
<br /> Cool to 425°C(800°0 at a rate <280°C (500°0.
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