Postweld Heat Treatment Requirements for Pressure Parts and Attachments, Essays (high school) of Boilers and Welding

Download Postweld Heat Treatment Requirements for Pressure Parts and Attachments and more Essays (high school) Boilers and Welding in PDF only on Docsity! PART AF — FABRICATION REQUIREMENTS Table AF-402.1 TABLE AF-402.1 (CONT’D) REQUIREMENTS FOR POSTWELD HEAT TREATMENT OF PRESSURE PARTS AND ATTACHMENTS Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 6 1250 1 hr / in., 2 hr plus 15 min 2 hr plus 15 min Group Nos. 1, 2, 3 1 hr for each addi- for each addi- minimum tional inch over tional inch over 2 in. 2 in. NOTES: (1) Postweld heat treatment is not required for vessels constructed of Type 410 material with carbon content not to exceed 0.08% and welded with electrodes that produce an austenitic chromium-nickel weld deposit or a nonair-hardening nickel-chromium iron weld deposit, provided the plate thickness at the welded joint does not exceed 3⁄8 in., and for thicknesses over 3⁄8 in. to 11⁄2 in. provided a preheat of 450°F is maintained during welding and that the joints are completely radiographed. (2) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 7 1350 1 hr / in., 2 hr plus 15 min 2 hr plus 15 min Group Nos. 1, 2 1 hr for each addi- for each addi- minimum tional inch over tional inch over 2 in. 2 in. NOTES: (1) Postweld heat treatment shall be performed as prescribed in AF-402 except that the cooling rate shall be a maximum of 100°F per hour in the range above 1200°F, after which the cooling rate shall be sufficiently rapid to prevent embrittlement. Postweld heat treatment is not required for vessels constructed of Type 405 material with carbon content not to exceed 0.08%, welded with electrodes that produce an austenitic chromium-nickel weld deposit or a nonair-hardening nickel-chromium-iron weld deposit, provided the plate thickness at the welded joint does not exceed 3⁄8 in., and for thicknesses over 3⁄8 in. to 11⁄2 in. provided a preheat of 450°F is maintained during welding and that the joints are completely radiographed. (2) If during the holding period of postweld heat treatment, maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 8 . . . . . . . . . . . . NOTE: (1) Postweld heat treatment is neither required nor prohibited for joints between austenitic stainless steels of the P-No. 8 group. See Nonmandatory Appendix D. 197 docsity.com Table AF-402.1 1998 SECTION VIII — DIVISION 2 TABLE AF-402.1 (CONT’D) REQUIREMENTS FOR POSTWELD HEAT TREATMENT OF PRESSURE PARTS AND ATTACHMENTS Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 9A 1100 1 hr / in., 1 hr / in. 5 hr plus 15 min Group No. 1 1 hr for each addi- minimum tional inch over 5 in. NOTES: (1) When it is impractical to postweld heat treat at the temperature specified in this Table, it is permissible to carry out the postweld heat treatment at lower temperatures (1000°F minimum) for longer periods of time in accordance with Table AF-402.2. When postweld heat treatment is performed in accordance with this Note, the vessel test plate required by Article T-2 shall receive the same heat treatment. (2) Except for exemptions in Note (3), postweld heat treatment is mandatory under the following conditions: (a) on material over 5⁄8 in. nominal thickness. For material up to and including 5⁄8 in. nominal thickness, postweld heat treatment is mandatory unless a welding procedure qualification described in AF-210.4 has been made in equal or greater thickness than the production weld. (b) on material of all thicknesses if required by AG-301.1(c) or if for pressure parts subject to direct firing. (3) Postweld heat treatment is not mandatory under the conditions specified below: (a) for circumferential butt welds in pipe or tubes where the pipe or tubes comply with all of the following conditions: (1) a maximum nominal outside diameter of 4 in.; (2) a maximum thickness of 1⁄2 in.; (3) a maximum specified carbon content of not more than 0.15% (SA Material Specification carbon content, except when further limited by the purchaser to a value within the Specification limits); (4) a minimum preheat of 250°F. (b) for pipe or tube materials meeting the requirements of (3)(a)(1), (3)(a)(2), and (3)(a)(3) above, having attachments fillet welded to them, provided: (1) the fillet welds have a throat thickness of 1⁄2 in. or less; (2) the material is preheated to 250°F minimum. A lower preheating temperature may be used provided specifically controlled procedures necessary to produce sound welded joints are used. Such procedures shall include but not be limited to the following: (a) the throat thickness of fillet welds shall be 1⁄2 in. or less; (b) the maximum continuous length of fillet welds shall be not over 4 in.; (c) the thickness of the test plate used in making the welding procedure qualification of Section IX shall not be less than that of the material to be welded. (c) for attaching nonpressure parts to pressure parts with groove welds not over 1⁄2 in. in size or fillet welds that have a throat thickness of 1⁄2 in. or less, provided preheat to a minimum temperature of 200°F is applied; (d ) for studs welded to pressure parts provided preheat to a minimum temperature of 200°F is applied; (e) for corrosion resistant weld metal overlay cladding or for welds attaching corrosion resistant applied lining (see AF-551), provided preheat to a minimum temperature of 200°F is maintained during application of the first layer. (4) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. 198 docsity.com PART AF — FABRICATION REQUIREMENTS Table AF-402.1 TABLE AF-402.1 (CONT’D) REQUIREMENTS FOR POSTWELD HEAT TREATMENT OF PRESSURE PARTS AND ATTACHMENTS Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10B 1100 1 hr / in., 1 hr / in. 1 hr / in. Group No. 2 1 hr minimum NOTES: (1) Postweld heat treatment is mandatory for P-No. 10B materials for all thicknesses. (2) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10E 1250 1 hr / in., 1 hr / in. 1 hr / in. Group No. 1 1 hr minimum NOTES: (1) For SA-268 Grade TP446 material only, the cooling rate shall be a maximum of 100°F/hr in the range above 1200°F after which the cooling rate shall be sufficiently rapid to prevent embrittlement. (2) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10F 1100 1 hr / in., 1 hr / in. 1 hr / in. Group No. 6 1 hr minimum NOTES: (1) Postweld heat treatment is mandatory for P-No. 10F materials for all thicknesses. (2) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. 201 docsity.com Table AF-402.1 1998 SECTION VIII — DIVISION 2 TABLE AF-402.1 (CONT’D) REQUIREMENTS FOR POSTWELD HEAT TREATMENT OF PRESSURE PARTS AND ATTACHMENTS Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10G . . . . . . . . . . . . Group No. 1 NOTES: (1) Postweld heat treatment is neither required nor prohibited. (2) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10H . . . . . . . . . . . . Group No. 1 NOTE: (1) For the austenitic–ferritic wrought or cast duplex stainless steels listed below, postweld heat treatment is neither required nor prohibited, but any heat treatment applied shall be performed as listed below and followed by liquid quenching or rapid cooling by other means: Alloy Postweld Heat Treatment Temperature, °F S32550 1900–2050 S31803 1870–2010 S32900 (0.08 max. C) 1725–1750 S31200 1900–2000 S31500 1785–1875 S32304 1740–1920 J93345 2050 minimum S32750 1800–2060 S32950 1825–1875 Minimum Holding Time at Normal Temperature Normal Holding for Nominal Thickness (See AF-402.1) Temperature, Material °F, Minimum Up to 2 in. Over 2 in. to 5 in. Over 5 in. P-No. 10I 1350 1 hr / in., 1 hr / in. 1 hr / in. Group No. 1 1 hr minimum NOTES: (1) The cooling rate shall be a maximum of 100°F/hr in the range above 1200°F after which the cooling rate shall be rapid to prevent embrittlement. (2) Postweld heat treatment is neither required nor prohibited for a thickness of 1⁄2 in. or less. (3) For alloy S44635, the rules for ferritic chromium stainless steel shall apply, except that postweld heat treatment is neither prohibited nor required. If heat treatment is performed after forming or welding, it shall be performed at 1850°F minimum followed by rapid cooling to below 800°F. (4) If during the holding period of postweld heat treatment, the maximum time or temperature of any vessel component exceeds the provisions of AM-202, additional test coupons shall be made and tested. 202 docsity.com