ASTM A751-2020 pdf free download
ASTM A751-2020 pdf free download.Standard Test Methods and Practices for Chemical Analysis of Steel Products
1. Scope
1.1 These test methods and practices cover definitions, reference methods, practices, and guides relating to the chemi- cal analysis of steel, stainless steel, and related alloys. They include both wet chemical and instrumental techniques. 1.2 Directions are provided for handling chemical requirements, product analyses, residual elements, and refer- ence standards, and for the treatment and reporting ofchemical analysis data. 1.3 These test methods and practices apply only to those product standards which include these test methods and practices, or parts thereof, as a requirement. 1.4 In cases of conflict, the product specification require- ments shall take precedence over the requirements of these test methods and practices. 1.5 Attention is directed to ISO/IEC 17025 when there may be a need for information on criteria for evaluation of testing laboratories. 1.6 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. 1.7 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.
3. Terminology
3.1 Definitions: 3.1.1 For definitions ofterms used in these test methods and practices, see Terminology A941. 3.2 Definitions ofTerms Specific to This Standard: 3.2.1 product, check, or verification analysis, n—a chemical analysis of the semifinished or finished product, usually for the purpose of determining conformance to the specification re- quirements. 3.2.1.1 Discussion—The range of the specified composition applicable to product analysis is normally greater than that applicable to heat analysis in order to take into account deviations associated with analytical reproducibility (Note 1) and the heterogeneity of the steel. N OTE 1—All of the chemical analysis procedures referenced in these test methods include precision statements with reproducibility data, with the exception of Test Methods E50. 3.2.2 product analysis tolerances, n—a permissible varia- tion over the maximum limit or under the minimum limit of a specified element and applicable only to product analyses, not cast or heat analyses (Note 2). N OTE 2—The term “analysis tolerance” is often misunderstood. It does not apply to cast or heat analyses determined to show conformance to specified chemical limits. It applies only to product analysis and becomes meaningful only when the heat analysis ofan element falls close to one of the specified limits. For example, stainless steel UNS 30400 limits for chromium are 18.00 to 20.00 %. A heat that the producer reported as 18.01 % chromium may be found to show 17.80 % chromium by a user performing a product analysis. If the product analysis tolerance for such a chromium level is 0.20 %, the product analysis of 17.80 % chromium would be acceptable. A product analysis of 17.79 % would not be acceptable. 3.2.3 proprietary analytical method, n—a non-standard ana- lytical method, not published by ASTM, utilizing reference standards traceable to the National Institute of Standards and Technology (NIST), when available, or other sources refer- enced in Section 10.3.2.5 certified reference material, n—a specimen ofmaterial specially prepared, analyzed, and certified for chemical content under the jurisdiction of a recognized standardizing agency or group, such as the NIST, for use by analytical laboratories as an accurate basis for comparison. 3.2.5.1 Discussion—Reference samples should bear suffi- cient resemblance to the material to be analyzed so that no significant differences are required in procedures or corrections (for example, for interferences or inter-element effects). 3.2.6 working reference materials, n—reference materials used for routine analytical control and traceable to NIST standards and other recognized standards when appropriate standards are available.
