ASME SA-435:2021 pdf free download – Standard Specification for Straight-Beam Ultrasonic Examination of Steel Plates
1.Scope
1.1 This specification covers the procedure and acceptancestandards for straight-beam,pulse-echo,ultrasonic examina-tion of rolled fully killed carbon and alloy steel plates，1/2 in.[12.5 mm] and over in thickness. It was developed to assuredelivery of steel plates free of gross internal discontinuitiessuch as pipe,ruptures，or laminations and is to be usedwhenever the inquiry,contract，order,or specification statesthat the plates are to be subjected to ultrasonic examination.1.2 Individuals performing examinations in accordance withthis specification shall be qualified and certified in accordancewith the requirements of the latest edition of ASNT SNT-TC-1A or an equivalent accepted standard. An equivalentstandard is one which covers the qualification and certificationof ultrasonic nondestructive examination candidates and whichis acceptable to the purchaser.
1.3 The values stated in either inch-pound units or Sl unitsare to be regarded separately as standard. Within the text, theSl units are shown in brackets. The values stated in eachsystem are not exact equivalents，therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation.
1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards，Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.
4.Apparatus
4.1 The manufacturer shall furnish suitable ultrasonicequipment and qualified personnel necessary for performingthe test.The equipment shall be of the pulse-echo straight beamtype.The transducer is normally 1 to 1 /s in. [25 to 30 mm] indiameter or 1 in. [25 mm] square; however，any transducerhaving a minimum active area of 0.7 in.2[450 mm2] may beused, including phased-array probes using an equivalent activeaperture.The test shall be performed by one of the followingmethods: direct contact, immersion, or liquid column coupling.
4.2Other search units may be used for evaluating andpinpointing indications.
4.3 Vertical or horizontal linearity or both shall be checkedin accordance with Practice E317,Guide E2491，or anotherprocedure approved by the users of this specification. Anacceptable linearity performance may be agreed upon by themanufacturer and purchaser.
6.Procedure
6.1 Ultrasonic examination shall be made on either majorsurface of the plate.Acceptance of defects in close proximitymay require inspection from the second major surface. Platesordered in the quenched and tempered condition shall be testedfollowing heat treatment.
6.2 A nominal test frequency of 2V/4MHz is recommended.Thickness，grain size，or microstructure of the material andnature of the equipment or method may require a higher orlower test frequency. However,frequencies less than 1 MHzmay be used only on agreement with the purchaser. A clear,easily interpreted A-scan should be produced during theexamination.
6.3 Conduct the examination with a test frequency andinstrument adjustment that will produce a minimum 50 to amaximum 75 % of full scale reference back reflection from theopposite side of a sound area of the plate.
6.4 Scanning shall be continuous along perpendicular gridlines on nominal 9-in.[225-mm] centers,or at the manufac-turer’s option,shall be continuous along parallel paths，trans-verse to the major plate axis，on nominal 4-in. [100-mm]centers,or shall be continuous along parallel paths parallel tothe major plate axis，on 3-in. [75-mm] or smaller centers.Asuitable couplant such as water， soluble oil, or glycerin, shallbe used.