1941年，SAE钢铁部门与美国钢铁协会（AISI）合作，对SAE钢的成分范围表示方法进行了重大更改。现在应用的计划通常基于较窄的铸造或热分析范围，加上单个样品的某些产品分析余量，而不是以前为SAE钢中的碳和其他元素提供的固定范围和无公差限制。多年来，钢的化学成分的多样性一直是钢铁行业关注的问题。人们认识到，生产更少级别的钢可以提高交付量，并提供更好的机会来实现技术、制造实践和质量的进步，从而更充分地开发这些级别固有的应用可能性。 全面而公正的研究旨在确定所指定的许多等级中哪一个是最常见的要求，以及将具有类似要求的成分组合在一起的可行性。从这些研究中，选择了最常见的钢级，并将其保留在当前修订版中。表1、2、3A和3B给出了这些等级的铸造或热化学成分限值或范围。这些铸造或热极限或范围受SAE J409中给出的产品分析标准变化的影响。由于AISI不再发布钢材等级名称，因此本文件中列出的等级为SAE等级。 人们认识到，专业应用或加工有时需要除上述表格中所列化学成分以外的化学成分。当需要这种钢时，包括所需化学成分的元素以三种方式之一指定:（a）通过最小限度，（b）通过最大限度，或（c）通过最小和最大限度，称为范围。表4给出了碳钢各种元素的标准铸造或热分析限值和范围。在该表中，范围是最小和最大限值之间的算术差（即，0.19到0.25为0。 06范围）。这些铸造或热极限和范围也受SAE J409.ISTC第1部分中给出的产品分析标准变化的影响。ISTC制定了一个程序，允许维护本文件中的等级列表。这将涉及进行一项全行业的调查，以征求意见。该调查将按照技术委员会认为必要的频率进行。已经制定了在成绩表中增加或删除成绩的标准。新等级将根据符合SAE等级名称和化学性质的等级进行考虑，最低产量或消费量为225吨/年（250吨/年），并得到至少两个个人用户或生产商的赞助。 根据SAE J1081中的指南，新的钢成分将被视为潜在标准（PS）钢，直到新钢的生产达到生产或使用水平，使其有资格被视为标准钢。成绩的删除将以成绩调查为基础，协商一致。删除的等级将在SAE J1249中存档。当要求报告铸造或热分析以证明符合表1、2、3A或3B中所示的化学极限时，除了碳、锰、磷和硫的数量外，还应报告以下元素及其数量: 铜、铬、镍、钼和硅。当最后五种元素中任何一种的含量低于0.02%时，该分析可报告为“<0.02%”。根据2006年等级调查中的一个调查问题，等级表已被修订，所有产品形式的化学成分现在都合并为一个表。所列的化学范围将是除S含量外的各种产品形式的最窄范围。然而，众所周知，由于各种产品形式的截面尺寸不同，对产品形式的化学成分要求应该不同，以允许钢应用的足够灵活性。 这些差异反映在表4和表5中。

In 1941, the SAE Iron and Steel Division, in collaboration with the American Iron and Steel Institute (AISI), made a major change in the method of expressing composition ranges for the SAE steels. The plan, as now applied, is based in general on narrower cast or heat analysis ranges plus certain product analysis allowances on individual samples, in place of the fixed ranges and limits without tolerances formerly provided for carbon and other elements in SAE steels.For years the variety of chemical compositions of steel has been a matter of concern in the steel industry. It was recognized that production of fewer grades of steel could result in improved deliveries and provide a better opportunity to achieve advances in technology, manufacturing practices, and quality, and thus develop more fully the possibilities of application inherent in those grades.Comprehensive and impartial studies were directed toward determining which of the many grades being specified were the ones in most common demand, and the feasibility of combining compositions having like requirements. From these studies, the most common grades of steel have been selected and kept in the current revision. The cast or heat chemical composition limits or ranges of these grades are given inTables 1,2,3A, and3B. These cast or heat limits or ranges are subject to standard variations for product analysis as given in SAE J409. Since AISI is no longer issuing steel grade designations, grades listed in this document are SAE grades.It is recognized that chemical compositions other than those listed in the previously mentioned tables will at times be needed for specialized applications or processing. When such a steel is required, the elements comprising the desired chemical composition are specified in one of three ways: (a) by a minimum limit, (b) by a maximum limit, or (c) by minimum and maximum limits, termed a range.Standard cast or heat analysis limits and ranges for the various elements of carbon steels are given inTable 4. In this table, range is the arithmetical difference between the minimum and maximum limits (that is, 0.19 to 0.25 is a 0.06 range). These cast or heat limits and ranges are also subject to standard variations for product analysis as given in SAE J409.ISTC Division 1 has developed a procedure which allows for the maintenance of the grade lists in this document. This will involve conducting an industry-wide survey to solicit input. This survey will be conducted at a frequency deemed necessary by the technical committee.Criteria have been established for the addition to or the deletion of grades from the grade lists. New grades will be considered based on the grade meeting a SAE grade designation and chemistry, having a minimum production or consumption of 225 tonnes/year (250 tons/year) and has the sponsorship of at least two individual users or producers. New steel compositions will be considered as Potential Standard (PS) steels, based on the guidelines in SAE J1081, until such time as production of the new steel achieves a level of production or usage qualifying it for consideration as a standard steel.Deletion of grades will be by consensus based on the grade survey. Deleted grades will be archived in SAE J1249.When the cast or heat analysis is requested to be reported to demonstrate conformance to the chemical limits shown inTables 1,2,3A, or3B, in addition to the quantities of carbon, manganese, phosphorus, and sulfur, the following elements and their quantities shall also be reported: copper, chromium, nickel, molybdenum, and silicon. When the amount of any one of these last five elements is less than 0.02% that analysis may be reported as “<0.02%.”Based on a survey question in the 2006 Grade Survey, the grade lists have been revised such that chemistries of all product forms are now consolidated into single tables. The chemistry ranges listed will be the narrowest range for the various product forms with the exception of S content. It is acknowledged however that due to differences in the section size of the various product forms, chemical composition demands for the product forms should be different to allow for adequate flexibility of steel application. These differences are reflected inTables 4and5.