1.1 本指南涵盖ASTM小组委员会A01.02、A01.03、A01.06、A01.09、A01.11、A01.15、A01.19、A01.22和A01.28，以规定锻造碳钢、低合金钢和合金钢的化学成分限值。这些建议的等级成分限值适用于为碳钢、低合金钢和合金钢产品（包括非连续钢）制定标准的其他标准化机构。 1.2 本指南中包括确定指定化学成分的有效数字数量的建议。 1.3 上述ASTM小组委员会监管的所有标准中都包含了碳钢和合金钢等级，但适用于受限特殊最终用途的等级除外。 1.4 未解决的是特定ASTM小组委员会可能认为有必要进行的微小成分修改，以适应正常加工的影响或提高生产商或用户的可制造性，或两者兼而有之。 1.5 此外，还没有普遍解决（ASTM小组委员会设立的情况除外）所有限制的完全合理化问题，特别是当这些限制与长期实践相冲突，并且没有特殊技术效果证明其合理性时。 1.6 本指南不涉及停产或以前的标准钢等级。SAE J1249中列出了此类钢种。本指南中也不包括铸造材料和焊接填充金属。 1.7 1995年，AISI决定将维护其编号系统的责任移交给美国汽车工程师学会（SAE）（针对碳钢和合金钢）（SAE J403和SAE J404）和ASTM国际（针对不锈钢）（指南 A959型 和其他）。为了告知用户这一重要事件，本标准附录中包含了历史信息。 1.8 以英寸-磅单位表示的数值视为标准值。括号中给出的值是数学转换为SI单位，仅供参考，不被视为标准单位。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 预计ASTM小组委员会A01.02、A01.03、A01.06、A01.09、A01.11、A01.15、A01.19、A01.22和A01.28将针对其产品规范中确定的等级使用本指南中列出的标准成分限值，除非有具体的技术理由进行其他操作。 4.2 本指南中给出的成分限值将用作确定每个等级总成分中包含的每个元素的限值的指南。制定成分限制的目的是，每个ASTM小组委员会都会发现，为了反映具体的技术效果，只需要进行最少数量的更改。 部分 5. 列出了确定每个元素限制所遵循的一般准则；本指南中确定的限制基于这些指南。

1.1 This guide covers ASTM Subcommittees A01.02, A01.03, A01.06, A01.09, A01.11, A01.15, A01.19, A01.22, and A01.28 for specifying chemical composition limits of wrought carbon, low-alloy, and alloy steels. It is intended that these recommended grade composition limits be suitable for adoption by other standardization bodies that prepare standards for carbon, low-alloy, and alloy steel products, including discontinued steels. 1.2 Included in this guide are the recommendations for determining the number of significant figures for specifying chemical composition. 1.3 The carbon and alloy steel grades in all standards overseen by the aforementioned ASTM subcommittees have been included, except those grades applicable to restricted special end uses. 1.4 Not addressed are minor composition modifications that a specific ASTM subcommittee may find necessary to accommodate effects of normal processing or to enhance fabricability by the producer or user, or both. 1.5 Also not generally addressed (except where established by ASTM subcommittees) is a complete rationalization of all limits, especially where such would conflict with long-standing practices and is not justified by special technical effect. 1.6 This guide does not address discontinued or formerly standard steel grades. A listing of such steel grades can be found in SAE J1249. Also excluded from this guide are cast materials and welding filler metals. 1.7 In 1995, the AISI made the decision to transfer the responsibility of maintaining its numbering system to the Society of Automotive Engineers (SAE) for carbon and alloy steels (SAE J403 and SAE J404) and to ASTM International for stainless steels (Guide A959 and others). To inform users of this important event, historical information is included in the appendix of this standard. 1.8 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.9 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. ====== Significance And Use ====== 4.1 It is anticipated that the ASTM Subcommittees A01.02, A01.03, A01.06, A01.09, A01.11, A01.15, A01.19, A01.22, and A01.28 will use the standard composition limits listed in this guide for the grades identified in their product specifications unless there is a specific technical justification for doing otherwise. 4.2 The composition limits given in this guide are to be used as guides in determining limits for each of the elements included in the total composition of each grade. The composition limits have been established with the intent that each ASTM subcommittee will find it necessary to require only a minimum number of changes to reflect specific technical effects. Section 5 lists the general guidelines followed for determining the limits for each element; the limits established in this guide are based upon these guidelines.