ASTM-A751:14 pdf free download – StandardTest Methods, Practices, and Terminology for Chemical Analysis of Steel Products.
4.3 For those cases in which the composition range spans either 0.10 % or 3.0 %, the number of figures to the right of the decimal is to be determined by that indicated by the upper limit.
4.4 Technical considerations may dictate the employment of less than the number of figures to the right of the decimal as previously recommended.
NOTE 3—The recommendations should be employed to reduce the number of significant figures, such as from 18.00% to 18.0%, but a significant figure should never be added unless there is a technical reason for so doing.
5. Cast or Heat Analysis
5.1 The producer shall perform analyses for those elements specified in the material specification. The results of such analyses shall conform to the requirements specified in the material specification.
5.1.1 For multiple heats, either individual heat or cast analysis or an average heat or cast analysis shall he reported. If significant variations in heat or cast size are involved, a weighted average heat or cast analysis, based on the relative quantity of metal in each heat or cast, shall be reported.
5.1 .2 For consumable electrode remelted material, a heat is defined as all the ingots remelted by the same process from a primary heat. The heat analysis shall he obtained from one remelted ingot, or the product of one remelted ingot, from each primary melt. If this heat analysis does not meet the heat analysis requirements of the specification, one sample from the product of each remelted ingot shall be analyzed, and the analyses shall meet the heat analysis requirements.
5.2 lithe test samples taken for the heat analysis arc lost, inadequate, or not representative of the heat, a product analysis of the semifinished or finished product may be used to establish the heat analysis.
5.2.1 If a product analysis is made to establish the heat analysis, the product analysis shall meet the specified limits for heat analysis and the product analysis tolerances described in Section 6 do not apply.
6. Product Analysis Requirements
6.1 For product analysis, the range of the specified chemical composition is normally greater (designated product analysis tolerances) than that applicable to heat analyses to take into account deviations associated with analytical reproducibility and the heterogeneity of the steel. If several determinations of any element in the heat are made. they may not vary both above and below the specified range.
6.2 Product analysis tolerances may not be used to determine confoniiancc to the specified heat or cast analysis unless permitted by the individual material specification.