ASTM A418/A418M-15(2020)
- standard by ASTM International, 03/01/2020
- Standard Practice for Ultrasonic Examination of Turbine and Generator Steel Rotor Forgings
- Category: ASTM
$50.00
$25.00
Full Description
1.1 This practice for ultrasonic examination covers turbine and generator steel rotor forgings covered by Specifications A469/A469M, A470/A470M, A768/A768M, and A940/A940M. This practice shall be used for contact testing only.
1.2 This practice describes a basic procedure of ultrasonically inspecting turbine and generator rotor forgings. It does not restrict the use of other ultrasonic methods such as reference block calibrations when required by the applicable procurement documents nor is it intended to restrict the use of new and improved ultrasonic test equipment and methods as they are developed.
1.3 This practice is intended to provide a means of inspecting cylindrical forgings so that the inspection sensitivity at the forging center line or bore surface is constant, independent of the forging or bore diameter. To this end, inspection sensitivity multiplication factors have been computed from theoretical analysis, with experimental verification. These are plotted in Fig. 1 (bored rotors) and Fig. 2 (solid rotors), for a true inspection frequency of 2.25 MHz, and an acoustic velocity of 2.30 in./s × 105 in./s [5.85 cm/s × 105 cm/s]. Means of converting to other sensitivity levels are provided in Fig. 3. (Sensitivity multiplication factors for other frequencies may be derived in accordance with X1.1 and X1.2 of Appendix X1.)
FIG. 1 Bored Forgings
Note 1: Sensitivity multiplication factor such that a 10 % indication at the forging bore surface will be equivalent to a 1/8 in. [3 mm] diameter flat bottom hole. Inspection frequency: 2.0 MHz or 2.25 MHz. Material velocity: 2.30 in./s × 105 in./s [5.85 cm/s × 105 cm/s].
FIG. 2 Solid Forgings
Note 1: Sensitivity multiplication factor such that a 10 % indication at the forging centerline surface will be equivalent to a 1/8 in. [3 mm] diameter flat bottom hole. Inspection frequency: 2.0 MHz or 2.25 MHz. Material velocity: 2.30 in./s × 105 in./s [5.85 cm/s × 105 cm/s].
FIG. 3 Conversion Factors to Be Used in Conjunction with Fig. 1 and Fig. 2 if a Change in the Reference Reflector Diameter is Required
1.4 Considerable verification data for this method have been generated which indicate that even under controlled conditions very significant uncertainties may exist in estimating natural discontinuities in terms of minimum equivalent size flat-bottom holes. The possibility exists that the estimated minimum areas of natural discontinuities in terms of minimum areas of the comparison flat-bottom holes may differ by 20 dB (factor of 10) in terms of actual areas of natural discontinuiti
Product Details
- Published:
- 03/01/2020
- Number of Pages:
- 8
- File Size:
- 1 file , 210 KB
- Note:
- This product is unavailable in Russia, Ukraine, Belarus
Document History
ASTM A418/A418M-15(2020)
ASTM A418/A418M-15
ASTM A418/A418M-09
ASTM A418-99(2003)
ASTM A418-99
ASTM C1515-14
Standard Guide for Cleaning of Exterior Dimension Stone, Vertical And Horizontal Surfaces, New or ..
$31.00 $62.00
ASTM D2521/D2521M-76(2014)e1
Standard Specification for Asphalt Used in Canal, Ditch, and Pond Lining..
$27.00 $54.00
ASTM D6826-05(2014)e1
Standard Specification for Sprayed Slurries, Foams and Indigenous Materials Used As Alternative Da..
$30.00 $60.00