ASME PTB- 13-2021 pdf download
ASME PTB- 13-2021 pdf download.CRITERIA FOR PRESSURE RETAINING METALLIC COMPONENTS USING ADDITIVE MANUFACTURING.
Commentary The Additive Manufacturer is required to prepare a Powder Specification for all AM builds. The Powder Specification shall specify all pertinent powder properties data and powder processing requirements necessary to ensure the material meets the requirement of the ASME material specification following additive processing. The powder specification shall include acceptance criteria for all required testing. The test methods provided in ISO/ASTM 52907 [6] are recommended for all testing, but it is recognized that other testing criteria may be used. The criteria prescribe a minimum set of tests to be performed, but the Additive Manufacturer may require additional testing as deemed necessary for the specific AM component construction. The criteria allow for reuse of powder when the blended batch of used powder meets all testing requirements in the powder specification identified in the AM Specification. The AM criteria for powder do not allow the use of elemental powders to be blended to the composition proportions identified in the material specification. The powder particles are to individually represent the alloy composition of the ASME material specification to limit or eliminate the potential risk of an inhomogeneous composition that could be experienced when mixing elemental powders. The Powder Supplier is required to provide a certified test report to the Additive Manufacturer which confirms that the powder conforms to the Powder Specification.
(l) Two metallographic evaluations shall be performed on material qualification specimens for locations PQ1-PQ7. One specimen shall be from a region near the bottom of the build volume and one specimen shall be from a region near the top of the build volume. (m) One hardness test shall be performed on a material qualification specimen for each qualification build in the region having the highest measured tensile strength. (n) One material qualification specimen shall be provided for chemical composition testing at a location determined by the Additive Manufacturer. (o) When supplemental material testing is required as part of the Additive Manufacturing Specification, the material for the test specimens shall be produced as part of either the initial qualification builds or supplementary qualification builds. (p) When additional material qualification specimens are required, the material for the specimens shall be located within 3/8 in. (10 mm) of tensile test specimens at locations of limiting material conditions. (q) The results of the required testing shall be documented in a Procedure Qualification Test Report certified by the Additive Manufacturer. The Procedure Qualification Record and the Machine Qualification Record provided in AWS D20.1 [7] may be used as a guide in completing the Qualification Test Report for the qualification builds. (r) The Procedure Qualification Test Report shall identify the locations of limiting material conditions for each energy source for use in Component Qualification and Production Testing. (s) The Procedure Qualification Test Report shall identify the variation in material properties across the build volume. (t) The Procedure Qualification Test Report shall be included in the Additive Manufacturer’s construction records.
Commentary The successful application of additive manufacturing requires rigorous qualification testing to achieve control of the AM Process. The AM Special Committee chose to specify performance-based criteria for acceptance of the AM procedure qualification. The Additive Manufacturer is required to complete sufficient qualification builds to produce sufficient material qualification specimens to support with 95% confidence that 99% of the produced material is in accordance the ASME material specification. The performance-based criteria were used instead of requiring a specific number of qualification samples. The performance basis criteria are intended to provide a graded approach to procedure qualification that will distinguish between the level of experience the additive manufacturer has with a specific AM machine and material. A new machine and first use of a material will require more testing than well-characterized AM machines and materials. The AM Procedure Qualification section lays out specific requirements for sample size, location, and type of material testing. The criteria require that the minimum wall thickness of an AM component built to a specific Additive Manufacturing Specification shall not be thinner than the minimum thickness qualified by the process qualification. To meet the requirements for fracture toughness testing, thicker test specimens will be required to comply with most applications.
