ASTM E588-03(R2020) pdf free download

ASTM E588-03(R2020) pdf free download.Standard Practice for Detection of Large Inclusions in Bearing Quality Steel by the Ultrasonic Method
1. Scope
1.1 This practice covers a procedure for the rating of rectangular steel sections by immersion ultrasonic techniques. Its purpose is to provide information on the content of large inclusions or clusters of small inclusions for determining the suitability of a steel lot for bearing applications. This practice in no manner defines or establishes limits of acceptability. 1.2 For this document, large inclusions are defined in ultrasonic terms as those having a reflecting area equivalent to or larger than a 1 ⁄ 64 in. diameter flat-bottom hole in a steel reference block of similar properties and thickness. In metal- lographic terms, large inclusions, defined in this way, are of approximately the same size as the smallest detectable sizes revealed by the macroscopic methods of Test Methods E45. In some cases, inclusions smaller than those described previously can be detected either individually or in clusters, depending on their type, chemical composition, orientation to the ultrasonic beam and distance from the sound entry surface of the specimen. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
8. Apparatus
8.1 Equipment Required—An equipment system with the following components is needed to conduct this test: ultrasonic test instrument, search unit, a means of recording signals of various amplitudes, a system reference block, instrument calibration block, and an immersion tank with suitable scan- ning accessories. 8.2 Ultrasonic Instrument—The ultrasonic instrument shall be capable of generating and receiving electrical pulses of 10 MHz frequency at levels compatible with the test requirements. It shall have both an A-scan presentation and an analog or digital output. It shall be the ultrasonic instrument manufac- turer’s responsibility that instruments supplied for use with this test meet the minimum requirements delineated in this recom- mended practice. 8.2.1 Receiver Characteristics—The center frequency shall be 10 MHz 6 0.5 MHz. The bandpass of the receiver shall be at least 1.3 MHz (3 dB points). 8.2.2 Dynamic Range—The dynamic range of the instru- ment shall permit detection of steel balls with a 16 to 1 diameter ratio at a given sensitivity. Balls shall be placed in water at the focal point of the search unit. Each size ball within this range shall give a significantly different amplitude of indication. 8.2.3 Stability—The signal amplitude of a usable full-scale indication shall not vary more than 5 % after 1 h of instrument warm-up, and preferably by less than 2 % (4 h test with air temperature being held to 61.2 °C over a temperature range of 17.5 °C to 25.5 °C). 8.2.4 Sweep Length and Linearity—Sweep length of oscil- loscope presentation shall be capable of being adjusted to represent 1 mm = 1.27 mm of steel. A minimum of 80 mm of the sweep display shall be linear to within 5 % of full scale. The signal amplitude of an indication from a target shall not vary more than 64 % over the gated portion of the sweep employed in calibration and testing. 8.2.5 Repetition Rate—The repetition rate ofthe pulser shall not be less than 500 pulses per second. 8.3 Search Units—Ultrasonic search units for this test shall be spherically focused immersion-type units. Uniform perfor- mance characteristics of search units are critical for obtaining reproducible test measurements. (See Annex A1, which delin- eates search unit performance characteristics to be met by search unit manufacturers.) Performance characteristics of search units requiring consideration are: the uniformity offocal distance in water, center frequency, frequency spectrum, lens radius, width of field, and beam symmetry.