【国外标准】 Standard Test Methods for Chemical Analysis of Ferroniobium

4.1 These test methods for the chemical analysis of ferroniobium alloy are primarily intended to test such materials for compliance with compositional specifications such as Specification A550. It is assumed that all who use these test methods will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory.1.1 These test methods cover the chemical analysis of ferroniobium having chemical compositions within the following limits:  Element Composition, %  Aluminum 2.00 max  Carbon 0.30 max  Chromium 2.00 max  Cobalt 0.25 max  Lead 0.01 max  Manganese 3.00 max  Niobium 40.00 to 75.00  Phosphorus 0.05 max  Silicon 4.00 max  Sulfur 0.03 max  Tantalum 7.00 max  Tin 0.15 max  Titanium 5.00 max  Tungsten 0.50 max1.2 The test methods appear in the following order:  SectionsSeparation of Niobium, Tantalum, and Titanium by the Ion-Exchange Test Method 15 and 16   Titanium by the Spectrophotometric Test Method [0.05 % to 5.0 %] 17 – 21   Niobium by the Gravimetric Test Method [40 % to 75 %] 22 – 23   Tantalum by the Gravimetric Test Method [1 % to 7 %] 24 – 25   Tantalum by the Spectrophotometric Test Method [0.25 % to 1 %] 26 – 301.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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 consult and establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 6, and specific warning statements in 11.1.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.