1、Designation:A745/A745M94 (Reapproved 2009) Designation: A745/A745M 12Standard Practice forUltrasonic Examination of Austenitic Steel Forgings1This standard is issued under the fixed designation A745/A745M; the number immediately following the designation indicates the yearof original adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice2covers the standards and procedures for the contact, pulse-echo ultr
3、asonic examination of austenitic steelforgings by the straight or angle beam techniques, or both.1.2This practice shall be used whenever the inquiry, proposal, contract, order, or specification states that austenitic steel forgingsare to be subject to ultrasonic examination in accordance with Practi
4、ce A745/A745M. Ultrasonic examination of nonmagneticretaining ring forgings should be made to Practice covers straight and angle beam contact, pulse-echo ultrasonic examination ofaustenitic steel forgings produced in accordance with Practice A388/A388M and Specifications A965/A965M and A1049/A1049M.
5、1.2 Ultrasonic examination of nonmagnetic retaining ring forgings should be made to Practice A531/A531M , not to thispractice.1.3The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore
6、, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.4This practice and the applicable material specifications are expressed in both inch-pound units and SI units. However, unlessthe order specifies the applica
7、ble “M” specification designation SI units, the material shall be furnished to inch-pound units.rather than this practice.1.3 Supplementary requirements of an optional nature are provided for use at the option of the purchaser. The supplementaryrequirements shall apply only when specified individual
8、ly by the purchaser in the purchase order or contract.1.4 This practice is expressed in inch-pound and SI units; however, unless the purchase order or contract specifies the applicable“M” specification designation (SI units), the inch-pound units shall apply. The values stated in either inch-pound u
9、nits or SI unitsare to be regarded separately as standard. Within the practice, the SI units are shown in brackets. The values stated in each systemmay not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the twosystems may result in noncon
10、formance with the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations pri
11、or to use.2. Referenced Documents2.1 ASTM Standards:3A388/A388M Practice for Ultrasonic Examination of Steel ForgingsA531/A531M Practice for Ultrasonic Examination of Turbine-Generator Steel Retaining RingsA965/A965M Specification for Steel Forgings, Austenitic, for Pressure and High Temperature Par
12、tsA1049/A1049M Specification for Stainless Steel Forgings, Ferritic/Austenitic (Duplex), for Pressure Vessels and RelatedComponentsE317 Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments and Systems withoutthe Use of Electronic Measurement InstrumentsE42
13、8 Practice for Fabrication and Control of Metal, Other than Aluminum, Reference Blocks Used in Ultrasonic Testing2.2 American Society for Nondestructive Testing Document:41This practice is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct res
14、ponsibility of Subcommittee A01.06on Steel Forgings and Billets.Current edition approved AprilMarch 1, 2009.2012. Published April 2009.March 2012. Originally approved in 1977. Last previous edition approved in 20032009 asA745/A745M 94 (2003).(2009). DOI: 10.1520/A0745_A0745M-94R09. 10.1520/A0745_A07
15、45M-12.2For ASME Boiler and Pressure Vessel Code applications see related Specification SA-745/SA-745M in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informa
16、tion, refer to the standards Document Summary page on the ASTM website.4Available from the American Society for Nondestructive Testing, 1711 Arlingate Lane, P.O. Box 28518, Columbus, OH 432280518.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an i
17、ndication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to b
18、e considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.SNT-TC-1A Recommended Practice for Nondestructive Personnel Qualification and Certifi
19、cation3. Ordering Information3.1 When this practice is to be applied to an inquiry or purchase order, the purchaser shall furnish the following information:3.1.1 Quality level of examination (see Section 12).3.1.2 Additional requirements to this practice.3.1.3 Applicability of supplementary requirem
20、ents (see Supplementary Requirements section).3.1.4 Supplementary requirements, if any.3.2 When specified, the manufacturer shall submit an examination procedure for purchaser approval that shall include, but notbe limited to, a sketch of the configuration as presented for ultrasonic examination sho
21、wing the surfaces to be scanned, scanningdirections, notch locations and sizes (if applicable), extent of coverage (if applicable), and an instruction listing calibration andinspection details and stage of manufacture.4. Apparatus4.1An electronic, pulsed, reflection type of instrument shall be used
22、for this examination. The system shall have a minimumcapability for operating at frequencies from 0.5 to 5.0 MHz. Either video or r-f presentation is acceptable.4.2The ultrasonic instrument shall provide linear presentation (within 6 5% of the signal height) for at least 75% of the screenheight (swe
23、ep line to top of screen). This 5% linearity is descriptive of the screen presentation of amplitude. Instrument linearityshall be verified in accordance with the intent of Practice4.1 Electronic ApparatusA pulse-echo instrument permitting inspection frequencies of 1, 2.25, and 5 MHz is required. The
24、accuracy of discontinuity amplitude analysis using this practice involves a knowledge of the true operating frequency of thecomplete inspection system. One of the best ways to obtain the desired accuracy is by use of a tuned pulser and narrow bandamplifier of known frequency response, with either a
25、broadband transducer, or a narrow-band tuned transducer of known andmatching frequency.4.1.1 Apparatus Qualification and CalibrationBasic qualification of the ultrasonic test instrument shall be performed atintervals not to exceed 12 months or whenever maintenance is performed that affects the equip
26、ment function. The date of the lastcalibration and the date of the next required calibration shall be displayed on the test equipment.4.1.2 The horizontal linearity shall be checked on a distance calibration bar using the multiple order technique (see PracticeE317.4.3Instruments with incremental gai
27、n control (accurate over its useful range to 6 10% of the nominal attenuation ratio) shallbe used when possible to allow measurement of signals beyond the linear display range of the instrument. ). The horizontal linearityshall be 62 % of the metal path.4.1.3 The accuracy of the linearity shall be c
28、hecked by ultrasonically verifying the thickness of the component in at least onelocation beyond the near field of the transducer. If necessary, minor adjustments for differences in the ultrasonic velocities betweenthe calibration bar and the forging shall then be made.4.2 AmplifierThe amplifier and
29、 display shall provide linear response within 62 %, up to 100 % of full screen height.4.2.1 Amplifier CalibrationAn amplifier vertical linearity check shall be made prior to performing the test by observing amultiple order pattern from a calibration block using a 2.25 MHz transducer (see Practice E3
30、17). The first back reflection shall beset at 100 % of full screen height. The higher order back reflections, 10 % and higher in amplitude, shall also be positioned onthe screen and their amplitudes noted. The first back reflection shall be reduced to 50 % and then 25 % of full screen height. Theamp
31、litudes of the higher order back reflections shall be noted at each step. The vertical linearity will be considered acceptable ifthe signal heights of the higher order reflections decrease in proportion to the decrease set for the first back reflection. Themaximum acceptable error for the decrease o
32、f the higher order reflections is the greater of 65 % of the expected back reflectionheight or 62 % of full screen height.4.3 Signal AttenuatorThe instrument shall contain a calibrated gain control or signal attenuator that meets the requirementsof Practice E317 (in each case, accurate within 65 %)
33、that will allow indications beyond the linear range of the instrument to bemeasured. It is recommended that these controls permit signal adjustments up to 25 to 1 (28 dB).4.4 Search Units:4.4.1Search units having transducers of either quartz or other piezoelectric materials may be employed.4.4.2The
34、maximum nominal active area of 1124.4.1 The maximum nominal active area of 112 in.2970 mm2 with12-in. 13 mm minimum to 118-in. 30 mm maximumdimensions or34-in. 20 mm diameter minimum dimension shall be used for straight-beam scanning.4.4.32 Angle-beam scanning transducers shall have a nominal active
35、 area of12 to 1 in.2325 to 650 mm2. The search unit usedfor angle-beam examination shall produce a beam angle of 30 to 70 in the material.4.4.43 Other search units, including frequencies other than those listed in Section 8 , may be used for evaluating and pinpointingindications of discontinuities.4
36、.5 CouplantA suitable couplant having good wetting characteristics shall be used between the transducer and theexamination surface. The same couplant shall be used for calibration and examination.4.6 Reference Blocks:A745/A745M 1224.6.1 All ultrasonic standard reference blocks shall be in accordance
37、 with the general guidelines of Practice E428. However,absolute conformance to Practice E428 is not mandatory due to the nature of the material covered by this practice.4.6.2 The reference block grain size, as measured by the relative acoustic penetrability of the reference blocks, should bereasonab
38、ly similar to the forging under examination. However, it must be recognized that large austenitic forgings varyconsiderably in acoustic penetrability throughout their volume due to variations in grain size and structure. Reference blocksshould be chosen that reasonably approximate the average penetr
39、ability of the forging under examination. Supplementary blocksof coarser or finer grain may be used for evaluation of indications as covered in Section 11.4.6.3 As an alternative method, where practicable, the appropriate size of reference hole (or holes) or notches may be placedin representative ar
40、eas of the forging for calibration and examination purposes when removed by subsequent machining. Whenholes or notches are not removed by subsequent machining, the purchaser must approve the location of holes or notches.5. Personnel Requirements5.1 Personnel performing the ultrasonic examinations to
41、 this practice shall be qualified and certified in accordance with a writtenprocedure conforming to Recommended Practice No. SNT-TC-1A or another national standard that is acceptable to both thepurchaser and the supplier.6. Forging Conditions6.1 Forgings shall be ultrasonically examined after heat t
42、reating.6.2 The surfaces of the forging to be examined shall be free of extraneous material such as loose scale, paint, dirt, etc.6.3 The surface roughness of scanning surfaces shall not exceed 250 in. 6 m unless otherwise stated in the order or contract.6.4 The forgings shall be machined to a simpl
43、e configuration, that is, rectangular or parallel or concentric surfaces wherecomplete volumetric coverage can be obtained.6.5 In certain cases, such as with contour forged parts, it may be impractical to assure 100 % volumetric coverage. Such forgingsshall be examined to the maximum extent possible
44、. A procedure indicating the extent of examination coverage shall be submittedfor the purchasers approval (see 3.2).7. Procedure7.1 Perform the ultrasonic examination after heat treatment when the forging is machined to the ultrasonic configuration butprior to drilling holes, cutting keyways, tapers
45、, grooves, or machining sections to final contour.7.2 To ensure complete coverage of the forging volume when scanning, index the search unit with at least 15 % overlap witheach pass.7.3 The scanning rate shall not exceed 6 in. 150 mm/s.7.4 Scan all regions of the forging in at least two perpendicula
46、r directions to the maximum extent possible.7.5 Scan disk and disk-type forgings using a straight beam from at least one flat face and radially from the circumference whenpracticable. For the purposes of this practice, a disk is a cylindrical shape where the diameter dimension exceeds the heightdime
47、nsion. Disk-type forgings made as upset-forged “pancakes” shall be classified as disks for inspection purposes although at thetime of inspection, the part may have a center hole, counterturned steps, or other detail configuration.7.6 Scan cylindrical sections, ring and hollow forgings from the entir
48、e external surface (sides or circumference), using thestraight-beam technique, and scan the forging in the axial direction to the extent possible. When the length divided by the diameterratio (slenderness ratio) exceeds 6 to 1 (or axial length exceeds 24 in. 600 mm), scan axially from both end surfa
49、ces to the extentpossible. If axial penetration is not possible due to attenuation, angle-beam examination directed axially may be substituted in placeof axial straight beam. Examine ring and hollow forgings having an outside-diameter to inside-diameter ratio of less than 2 to 1and a wall thickness less than 8 in. 200 mm by angle-beam techniques from the outside diameter or inside diameter, or both, usingfull node or half-node technique (see 10.1.2 and 10.1.3) as necessary to achieve either 100 % volumetric coverage or the extentof coverage defi
