GB/T 7736-2008 PDF EnglishUS$70.00 · In stock · Download in 9 seconds
GB/T 7736-2008: Ultrasonic inspecting method for macro-structure and imperfection of steel Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB/T 7736: Historical versions
GB/T 7736-2008: Ultrasonic inspecting method for macro-structure and imperfection of steel---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT7736-2008NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 77.040.20 H 26 Replacing GB/T 7736-2001 Ultrasonic inspecting method for macro-structure and imperfection of steel ISSUED ON: SEPTEMBER 11, 2008 IMPLEMENTED ON: MAY 01, 2009 Issued by: General Administration of Quality Supervision, Inspection and Quarantine; Standardization Administration of the People’s Republic of China. Table of ContentsForeword ... 3 1 Scope ... 4 2 Normative references ... 4 3 Terms and definitions ... 5 4 Method principle ... 5 5 Inspection method ... 5 6 Comparative test piece ... 7 7 Inspection equipment and its debugging ... 13 8 Inspection conditions and procedures ... 14 9 Result evaluation ... 14 10 Inspection report ... 15 Ultrasonic inspecting method for macro-structure and imperfection of steel1 ScopeThis Standard specifies the terms and definitions, method principle, inspection methods, requirements and preparation of comparative test pieces, inspection equipment and its debugging, inspection conditions and procedures, result evaluation and inspection report of ultrasonic inspection for macro-structure and imperfection of steel. This Standard applies to ultrasonic inspection of macro-structure imperfection in rolled, forged steel (blank) with simple cross sections, such as square, rectangular, and circle.2 Normative referencesThe terms in the following documents become the terms of this Standard by reference to this Standard. For dated references, all subsequent amendments (not including errata content) or revisions do not apply to this standard. However, parties to agreements that are based on this Standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest edition applies to this Standard. GB/T 226, Test method for macrostructure and defect of steel by etching (GB/T 226-1991, neq ISO 4969:1980) GB/T 1979, Standard diagrams for macrostructure and defect of structural steels GB/T 11259, Practice for fabrication and control of steel reference blocks used in ultrasonic testing GB/T 12604.1, Non-destructive testing - Terminology - Terms used in ultrasonic testing JB/T 10061, Commonly used specification for A-mode ultrasonic flaw detector using pulse echo technique JB/T 10062, Testing methods for performance of probes used in ultrasonic flaw detection3 Terms and definitionsTerms and definitions determined by GB/T 12604.1 are applicable to this Standard. 4 Method principle 4.1 General principle Use the ultrasonic echo method; use the principle that echo occurs at different acoustic impedance interfaces during the propagation of ultrasonic waves in steel for flaw detection. 4.2 Small signal overlay The ultrasonic flaw detection method is a display of the flaw status within a certain volume range. Although the size of a single flaw is smaller than the specified limit of detection, the overlay of signals from many small flaw groups makes detection of the flaw group possible. 4.3 Structure echo The acoustic impedance changes which are caused by chemical composition segregation and inhomogeneity of structure in macro-structure can still obtain a sufficiently large echo signal in ultrasonic detection. This phenomenon of ultrasonic echo that is caused by macro-structure is called structure echo. 4.4 Flaw equivalent Adopt equivalent calibration of short horizontal hole artificial flaw and big flat- bottomed hole artificial flaws, or use big flat-bottomed equivalent calculation. 5 Inspection method Use longitudinal or horizontal waves to perform ultrasonic inspection along the peripheral surface of the steel (blank). The contact method or immersion method can be used. A coupling medium of good coupling effect and harmless to the human body and the steel surface shall be selected. 5.1 Contact method Use a single-straight probe to scan the workpiece in the far field; use a double- crystal probe to scan the workpiece in the near field. It shall be ensured that the entire workpiece scan coverage is good. It is recommended that when the diameter or side length of the to-be-inspected steel (blank) is not more than 207 Inspection equipment and its debugging7.1 Inspection equipment 7.1.1 The inspection equipment can be distinguished by the immersion method and the contact method. It is mainly composed of ultrasonic flaw detectors, probes, comparative samples, mechanical transmission devices and water tanks. Its comprehensive sensitivity shall reliably detect the artificial flaws which are specified in this Standard. 7.1.2 The flaw detector is a device that uses echo technique; the probe is a straight probe or a double-crystal probe; its electrical performance, combined performance and test method shall comply with the relevant provisions of JB/T 10061 and JB/T 10062. 7.1.3 In principle, the contact method flaw detection can choose straight probes or double-crystal probes of different frequencies and specifications according to the product specifications and requirements. 7.1.4 The immersion method can choose water-immersion probe or focus probe according to product specifications. 7.2 Equipment debugging 7.2.1 Each time when the flaw detection equipment is re-used or the specifications are replaced, the specified comparative test piece shall be used for static and dynamic debugging. 7.2.2 The static debugging mainly adjusts the artificial flaw wave amplitude, the alarm gate position and amplitude; when setting the alarm sensitivity, it shall be debugged according to the minimum amplitude of the flaw. If the equivalent calculation method is used, first adjust the initial sensitivity of the instrument, that is, adjust the first bottom echo height to 50% to 80% of the full scale of the phosphor screen in the intact part of the tested sample, as the reference of the evaluated echo signal. Then, according to the requirements of the tested sample, calculate the gain value that is needed to be increased according to Formula (2), to meet the debugging requirements of the specified sensitivity; then, perform the inspection. 7.2.3 The dynamic debugging mainly adjusts the appropriate scanning speed to ensure good reproducibility of the manual flaw detection limit. 7.2.4 The scanning speed of the manual operation of the contact method shall not be greater than 3 m/min. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 7736-2008 be delivered?Answer: The full copy PDF of English version of GB/T 7736-2008 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 7736-2008_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 7736-2008_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 7736-2008 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.Question 5: Should I purchase the latest version GB/T 7736-2008?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 7736-2008 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically.How to buy and download a true PDF of English version of GB/T 7736-2008?A step-by-step guide to download PDF of GB/T 7736-2008_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB/T 7736-2008". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
