ASME B16.49-2017 pdf download.Factory-Made, Wrought Steel, Buttwelding Induction Bends for Transportation and Distribution Systems.
8.1 Tensile Properties The tensileproperties shall be determinedforthequali- ficationbendinaccordancewithASTMA370.Theyield-to- tensile ratio shall not exceed 0.90, except for Grade P483 (X483) and higher, for which the ratio shall not exceed 0.93. When the strength of the bend does not meet the ordered strength, the manufacturer may provide, with purchaser approval, bends of comparable strength to the design pipe. The thickness of the bend shall be at least equal to the specified design pipe thickness multi- plied by the ratio ofthe specified minimum yield strength ofthe pipe and the minimum tested yield strength ofthe bend. For bends from welded pipe of NPS 8 (DN 200) or larger, a transverse weld tensile testin the final heat-treat condition shall be conducted to determine the ultimate tensile strength. See para. 11.1.1 for number, location, and orientation of test samples required.
8.3 Hardness Testing Hardness tests shall be performed in accordance with ASTM A370 on the bend as required in para. 11.1.4. To verify uniformity in the bending process, all production bends shall be tested forhardness in the same locations as thequalificationbend. Thecorrespondingareas shallhave average hardness readings not varying by more than 30 Brinell hardness, or equivalent, from the average value measured in the same location of the qualification bend, with no average equating to a tensile strength less than that required in Table 1 for the material grade marked on the bend. Use an average of at least three readings for each location tested. The type of portable hardness tester used on production bends shall be the same as used on the qualification bend. All testing shall be conducted in the final heat-treated condi- tion. No hardness measurement shall exceed the maximum specified in Table 1.
9 HEAT TREATMENT 9.1 Type Unless otherwise specified bythe purchaser, each bend shall be heat-treatedafterbending(exceptas permittedin para. SR15.1) by one or more of the following methods: (a) Stress Relieve or Temper. Uniformly, heat between 480°C (900°F) and 675°C (1,250°F) and hold at tempera- ture for at least 30 min per 25 mm (1 in.) of thickness at temperature, but no less than 30 min. (b) Normalize. Heatabovethetransformationtempera- ture range and hold at temperature for a minimum of20 min per 25 mm (1 in.) of thickness, but not less than 20 min, and allow to cool in still air. (c) Quench andTemper. Heatabove the transformation temperature range and hold at temperature for a minimum of 20 min per 25 mm (1 in.) of thickness and direct quench in either water, oil, or a synthetic quenchant. Reheat to temper as defined above.ASME B16.49 pdf download.