1、MSS SP-94-2015 Quality Standard for Ferritic and Martensitic Steel Castings and Forgings for Valves, Flanges, Fittings, and Other Piping Components Ultrasonic Examination Method Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry,
2、Inc. 127 Park Street, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standardsmsshq.org www.msshq.org MSS STANDARD PRACTICE SP-94i This MSS Standard Practice was developed under the consensus of the MSS Technical Committees 304 and the MSS Coordinating Committee. Th
3、e content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide an effective, clear, and non-exclusive standard that will benefit the industry as a whole. This MSS Standard Practice describes minimal requirements and is intended as a basis for common p
4、ractice by the manufacturer, the user, and the general public. The existence of an MSS Standard Practice does not in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance to this Standard Practice is established only by reference in
5、other documents such as a code, specification, sales contract, or public law, as applicable. MSS has no power, nor does it undertake, to enforce or certify compliance with this document. Any certification or other statement of compliance with the requirements of this Standard Practice shall not be a
6、ttributable to MSS and is solely the responsibility of the certifier or maker of the statement. “Unless indicated otherwise within this MSS Standard Practice, other standards documents referenced to herein are identified by the date of issue that was applicable to this Standard Practice at the date
7、of approval of this MSS Standard Practice (see Annex A). This Standard Practice shall remain silent on the validity of those other standards of prior or subsequent dates of issue even though applicable provisions may not have changed.” By publication of this Standard Practice, no position is taken w
8、ith respect to the validity of any potential claim(s) or of any patent rights in connection therewith. MSS shall not be held responsible for identifying any patent rights. Users are expressly advised that determination of patent rights and the risk of infringement of such rights are entirely their r
9、esponsibility. In this Standard Practice, all text, notes, annexes, tables, figures, and references are construed to be essential to the understanding of the message of the standard, and are considered normative unless indicated as “supplemental”. All appendices, if included, that appear in this doc
10、ument are construed as “supplemental”. Note that supplemental information does not include mandatory requirements. U.S. customary units in this Standard Practice are the standard; the SI (metric) units are for reference only. Substantive changes in this 2015 edition are “flagged” by parallel bars as
11、 shown on the margins of this paragraph. The specific detail of the change may be determined by comparing the material flagged with that in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Excerpts of this Standard Practice may be quot
12、ed with permission. Credit lines should read Extracted from MSS SP-94-2015 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or electronic transmission or dissemination is prohibited under copyright convention unless written
13、permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. Originally Approved: September 1983 Originally Published: December 1983 Current Edition Approved: March 2014/April 2015 Current Edition Published: December 2015 MSS is a re
14、gistered trademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright , 2015 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-94ii FOREWORD This MSS Standard Practice, SP-94, Quality
15、Standard for Ferritic and Martensitic Steel Castings and Forgings for Valves, Flanges, Fittings, and Other Piping Components Ultrasonic Examination Method, was originally adopted in 1983 for the purpose of providing industry with a uniform method of applying the Ultrasonic Examination procedure and
16、interpretation of the results. The Standard Practice was reaffirmed in 1987 with essentially no changes. The Third edition, issued in 1992, was revised to include a surface finish requirement for the calibration blocks. This was necessary as the previously referenced surface comparator of the Alloy
17、Casting Institute was no longer available. The 1999 edition included minor revisions and was re-formatted to conform to current MSS publication practices. The 2008 edition included minor revisions and was re-formatted to conform to current MSS publication practices. This 2015 edition includes editor
18、ial and substantive revisions that include the addition of “forgings” as part of the Scope and Title, identification of critical sections (as per ASME B16.34), revision of Figure 1 and 2, and other “flagged” changes. Additionally, this edition was re-formatted to conform to updated MSS publication p
19、ractices. MSS STANDARD PRACTICE SP-94iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 DEFINITTIONS 1 3 BASE FOR USE 1 4 EQUIPMENT 1 5 PERSONNEL REQUIREMENTS . 3 6 CASTING OR FORGING CONDITIONS 5 7 TEST CONDITIONS . 5 8 PROCEDURE 5 9 DATA REPORTING . 6 10 EVALUATION OF INDICATIONS . 6 11 ACCEPTANCE S
20、TANDARDS 8 TABLE 1 Dimensions and Identification of Reference Block in the Basic Set . 3 2 Dimensions of Calibration Blocks for Angle Beam Examination . 5 FIGURE 1 Ultrasonic Standard Reference Block 2 2 Basic Calibration Block for Angle Beam Examination . 4 ANNEX A Referenced Standards and Applicab
21、le Dates 9 MSS STANDARD PRACTICE SP-941 QUALITY STANDARD FOR FERRITIC AND MARTENSITIC STEEL CASTINGS AND FORGINGS FOR VALES, FLANGES, FITTINGS, AND OTHER PIPING COMPONENTS ULTRASONIC EXAMINATION METHOD 1. SCOPE1.1 This Standard Practice provides methods and acceptance standards for ultrasonic examin
22、ation of ferritic and martensitic steel castings and forgings for valves, flanges, fittings, and other piping components. This Standard Practice is applicable to the initial examination of castings and forgings and towards the examination of repairs. 1.2 The methods contained in this Standard Practi
23、ce describe uniform procedures that will provide satisfactory and consistent results upon which the acceptance standards of Section 11 may be used. 1.3 It is recognized that ultrasonic examination and radiographic examination are not directly comparable. This Standard Practice is intended to provide
24、 a casting or forging of functionally equivalent quality to those accepted by the method of MSS SP-54. 2. DEFINITIONSFor definitions of terms relating to ultrasonic testing, see ASTM E1316. 3. BASIS FOR USECritical sections of pressure containing castings and forgings, as identified by ASME B16.34,
25、shall be examined ultrasonically. 4. EQUIPMENT4.1 Electronic Apparatus 4.1.1 An ultrasonic, pulsed, reflection type of instrument which shall be capable of generating, receiving, and amplifying frequencies of at least l MHz to 5 MHz. 4.1.2 The ultrasonic equipment shall provide linear presentation (
26、within 5 percent) for at least 75 percent of the screen height (sweep line to top of screen). Linearity shall be determined in accordance with ASTM E317 or equivalent electronic means. 4.1.3 The electronic apparatus shall contain a single attenuator or calibrated gain control which shall be accurate
27、 over its useful range to 10 percent of the nominal attenuation or gain ratio to allow measurement of signals beyond the linear range of the instrument. 4.2 Search Units 4.2.1 Longitudinal Wave internally grounded search units having 1/2 to 118inch (13 to 29 mm) diameter or 1 inch (25 mm) square pie
28、zoelectric elements shall be used. Based on the signal-to-noise ratio of the response pattern of the casting or forging, a frequency in the range of 1 MHz to 5 MHz shall be used. The background noise shall not exceed 25 percent of the Distance Amplitude Correction (DAC) curve. Transducers shall be u
29、tilized at their rated frequencies. 4.2.2 Dual element 5 MHz search units are recommended for sections 1 inch (25 mm) and under in thickness. MSS STANDARD PRACTICE SP-942 FIGURE 1: Ultrasonic Standard Reference Block NOTES: (a) Opposite ends of reference block shall be flat and parallel within 0.001
30、 in. (0.03 mm). (b) Bottom of flat-bottom hole shall be flat within 0.002 in. (0.05 mm) and finished diameter shall be 0.250 0.002 in. (6.35 0.05 mm). (c) Hole shall be straight and perpendicular to entry surface within 0 deg. 30 min. and located within 1/32 in. (1 mm) of longitudinal axis. (d) Coun
31、ter bore shall be 1/2 in. (13 mm) diameter by 1/8 in. (3 mm) deep. LEGEND: B = Metal Distance of Reference Block C = Over-All Reference Block Length D = Width or Diameter of Reference Block (See Table 1) MSS STANDARD PRACTICE SP-943 TABLE 1: Dimensions and Identification of Reference Block in the Ba
32、sic Set Hole Diameter in. (mm) Metal Distance (B) in. (mm) Over-All Length (C) in. (mm) Width or Diameter (D), Minimum in. (mm) Block Identification Number 1/4 (6.35) 1/8 (3) 7/8 (22) 2 (50) 16-00125 1/4 (6.35) 1/4 (6) 1 (25) 2 (50) 16-0025 1/4 (6.35) 1/2 (13) 114 (32) 2 (50) 16-0050 1/4 (6.35) 3/4
33、(19) 112 (38) 2 (50) 16-0075 1/4 (6.35) 1 (25) 134 (44) 2 (50) 16-0100 1/4 (6.35) 2 (50) 234 (70) 2 (50) 16-0200 1/4 (6.35) 3 (75) 334 (95) 2 (50) 16-0300 1/4 (6.35) 6 (150) 634 (171) 3 (75) 16-0600 1/4 (6.35) 10 (250) 1034 (273) 4 (100) 16-1000 1/4 (6.35) B B + 3/4 (19) 5 (125) 16-B00 GENERAL NOTE:
34、 See Section 4.33 for additional supplemental blocks for testing thickness greater than 10 in. (250 mm). 4.2.3 Angle beam search units shall produce a shear wave beam in steel in the range of 40 to 75 inclusive, measured to the perpendicular of the entry surface of the casting or forging being exami
35、ned and having a frequency of 1 MHz to 5 MHz. 4.2.4 Other frequencies and sizes of search units may be used for evaluating and pinpointing indications. 4.3 Reference Blocks 4.3.1 Reference blocks shall be used to establish test sensitivity. 4.3.2 Reference blocks shall be made from steels that give
36、an acoustic response similar to the components being examined. 4.3.3 For single and dual element longitudinal wave transducers the design of reference blocks shall be in accordance with Figure 1 and the basic set shall consist of the blocks listed in Table 1. When section thicknesses over 10 inches
37、(250 mm) are to be inspected, an additional block of the maximum test thickness shall be made to supplement the basic set. 4.3.4 For angle beam transducers a set of blocks, as shown in Figure 2 and Table 2, with a surface equivalent to or smoother than 900 micro-inches (22.9 micrometers) and of a th
38、ickness comparable to the sections being examined with side drilled holes at 1/4t, 1/2t, and 3/4t (where t = thickness of the block) shall be used to establish a DAC curve. A basic set shall consist of those blocks listed in Table 2. 4.3.5 Each reference block shall be permanently identified along t
39、he side of the block indicating the material and the block identification. 4.4 Couplant A suitable couplant having good wetting characteristics shall be used between the search unit and examination surface. MSS STANDARD PRACTICE SP-944 5. PERSONNEL REQUIREMENTS 5.1 The manufacturer shall be responsi
40、ble for assigning qualified personnel to perform and interpret ultrasonic examinations in conformance with the requirements of this Standard Practice. 5.2 Personnel performing ultrasonic examinations in accordance with this specification shall be familiar with the following: a) Ultrasonic terminolog
41、y b) Instrument c) Effect of transducer material, size, frequency, and mode on test results. d) Effect of material structure (grain size, cleanliness, etc.) on test results. e) Effect of test distance on test results. f) Effect of nonlinearity on test results. g) Effect of thickness and orientation
42、of discontinuities on test results. h) Effect of surface roughness and geometry on test results. 5.3 A qualification record of personnel considered suitable by the manufacturer to perform and interpret examinations, in accordance with this Standard Practice, shall be available upon request. ASNT SNT
43、-TC-lA provides a recommended practice for qualifying personnel. FIGURE 2: Basic Calibration Block for Angle Beam Examination LEGEND: L = Length of block determined by the angle of search unit and the vee-path used T = Thickness of basic calibration block (see Table 2) D = Depth of side-drilled hole
44、 (see Table 2) d = Diameter of side-drilled hole (see Table 2) t = Nominal production material thickness MSS STANDARD PRACTICE SP-945 TABLE 2: Dimensions of Calibration Blocks for Angle Beam Examination Nominal Production Material Thickness (t) in. (mm) Basic Calibration Block Thickness (T) in. (mm)
45、 Hole Diameter (d) in. 0.002 (mm 0.05) Minimum Depth (D) in. (mm) Up to 1 (25) incl. 1 (25) or t 0.094 (2.38) 112 (38) Over 1 through 2 (25 through 50) 2 (50) or t 0.125 (3.18) 112 (38) Over 2 through 4 (50 through 100) 4 (100) or t 0.188 (4.76) 112 (38) Over 4 through 6 (100 through 150) 6 (150) or
46、 t 0.250 (6.35) 112 (38) Over 6 through 8 (150 through 200) 8 (200) or t 0.312 (7.94) 112 (38) Over 8 through 10 (200 through 250) 10 (250) or t 0.375 (9.53) 112 (38) Over 10 (250) t See NOTE (a) 112 (38) NOTE: (a) For each increase in thickness of 2 in. (50 mm), or fraction thereof, the hole diamet
47、er shall increase 1/16 in. (1.5 mm). GENERAL NOTE: For block sizes over 3 in. (75 mm) in thickness (T), the distance from the hole to the end of the block shall be 1/2 T min. to prevent coincident reflections from the hole and the corner. Block fabrication with a 2 in. (50 mm) minimum dimension need
48、 not be modified if the corner and hole indications can be easily resolved. 6. CASTING OR FORGING CONDITIONS 6.1 Castings or forgings shall receive at least an austenitizing heat treatment before being ultrasonically examined. 6.2 Test surfaces of castings or forgings shall be free of material such
49、as scale, weld spatter, etc. that will interfere with the ultrasonic examination. Test surfaces may be as cast, blasted, ground, or machined. 6.3 The ultrasonic examination shall be conducted prior to any machining that might prevent an effective examination of the casting or forging. 7. TEST CONDITIONS 7.1 To assure complete coverage of the specified casting or forged section, each pass of the search unit shall overlap by at least 10 percent of the width of the transducer. 7.2 The rate of scanning shall be appropriate for the surface condition but shall n
