1.1 宏观蚀刻是在低倍率下对试样进行宏观结构检查的蚀刻，是评估钢制品（如棒材、钢坯、初轧坯和锻件）的常用技术。 1.2 该方法包括通过显示特定条件发生率的分级系列照片对钢试样进行评级的程序。该方法仅适用于碳钢和低合金钢的棒材、坯料、初轧坯和锻件。 1.3 根据要进行的检查类型，可以使用多种不同的蚀刻试剂。由于化学成分、制造方法、热处理和许多其他变量的变化，钢对蚀刻试剂的反应不同。为所有条件制定验收或拒收的一般标准是不切实际的，因为某些条件必须考虑到其发生的部分。 1.4 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 请参阅中的具体预防说明 5.3 . 1.6 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. 宏观蚀刻用于钢铁行业，因为它是一种简单的测试，将提供有关样品相对均匀性的信息。该方法利用酸或其他腐蚀剂的作用来形成适当制备的试样的宏观结构特征。该名称意味着对蚀刻表面进行目视检查，或在低倍率（通常<10×）下进行检查。 4.2 宏观蚀刻将显示:( 1. )结构变化，如晶粒尺寸、树枝晶和柱状结构；( 2. )化学成分的变化，如离析、取芯和带状；而且( 3. )不连续性的存在，如搭接、接缝、裂缝、孔隙、爆裂、管道。还有雪花。 4.3 当根据询价、合同、订单或规范的要求，锻件、坯料、初轧坯等需要进行宏观浸蚀测试和检验时，制造商和买方应就以下事项达成一致: ( 1. )进行试验的制造阶段；( 2. )待检查部分的数量和位置；( 3. )试样蚀刻前的必要表面处理；( 4. )蚀刻试剂、蚀刻温度和时间；而且( 5. )有害条件的类型、大小、数量、位置和方向。 4.4 如果没有规定，制造商可以选择试验程序，以满足管理规范的要求。 4.5 经买方和生产商同意，铸态型材的硫印（如果连续铸造）是可接受的宏观蚀刻替代方案。硫磺印刷应按照惯例进行 E1180 . 试样的检查和评级应符合第节的规定 10 和 11 关于这个( E381 )标准。 4.6 锻制条件下的钢锭钢应根据第节所述程序进行检查 9 . 铸态条件下的连铸钢坯和钢坯应根据第节中所述的程序进行检查 10 和 11 . 当面积比减小到3:1以上时，可根据第节检查连铸钢的锻造产品 9 . 4.7 板I中的“R”系列照片不得用于评定A类偏析，有时也称为“碳点”和“硫偏析”A型在大型凝固铸锭液固区的通道中形成偏析，由于化学和微夹杂物含量与基体的差异，在最终锻件的蚀刻横截面上出现黑点，包括因去除原生硫化锰微夹杂物而产生的点蚀。它们在蚀刻纵断面中呈条纹状，含有较高水平的易偏析元素，如C、S、P、Si、Mn、Cr和硫化锰微夹杂物。 虽然A型隔离图案（包括伴随的MnS点蚀）在外观上与板I“R”系列照片中的条件有一些相似之处，但它们可以与R系列条件区别开来，因为它们围绕截面中心更对称地排列，并且在给定半径下，单个斑点的大小通常更均匀。附件一中的照片描述了A型隔离物的存在。应通过显微镜检查或其他检查手段验证可疑迹象的性质。

1.1 Macroetching, which is the etching of specimens for macrostructural examination at low magnifications, is a frequently used technique for evaluating steel products such as bars, billets, blooms, and forgings. 1.2 Included in this method is a procedure for rating steel specimens by a graded series of photographs showing the incidence of certain conditions. The method is limited in application to bars, billets, blooms, and forgings of carbon and low alloy steels. 1.3 A number of different etching reagents may be used depending upon the type of examination to be made. Steels react differently to etching reagents because of variations in chemical composition, method of manufacture, heat treatment and many other variables. Establishment of general standards for acceptance or rejection for all conditions is impractical as some conditions must be considered relative to the part in which it occurs. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.5 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 appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See the specific precautionary statement in 5.3 . 1.6 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 Macroetching is used in the steel industry because it is a simple test that will provide information about the relative homogeneity of the sample. The method employs the action of an acid or other corrosive agent to develop the macrostructural characteristics of a suitably prepared specimen. The name implies that the etched surface is examined visually, or at low magnifications (usually <10×). 4.2 Macroetching will show: ( 1 ) variations in structure such as grain size, dendrites, and columnar structure; ( 2 ) variations in chemical composition such as segregation, coring, and banding; and, ( 3 ) the presence of discontinuities such as laps, seams, cracks, porosity, bursts, pipe. and flakes. 4.3 When, in accordance with the requirements of the inquiry, contract, order or specifications, forgings, billets, blooms, etc., are to be produced subject to macroetch testing and inspection, the manufacturer and the purchaser should be in agreement concerning the following: ( 1 ) the stage of manufacture at which the test shall be conducted; ( 2 ) the number and locations of the sections to be examined; ( 3 ) the necessary surface preparation prior to etching of the specimen; ( 4 ) the etching reagent, temperature, and time of etching; and, ( 5 ) the type, size, number, location, and orientation of conditions that are to be considered injurious. 4.4 When not specified, the procedures of the test may be selected by the manufacturer to satisfy the requirements of the governing specification. 4.5 When agreed upon by purchaser and producer, sulfur printing of as cast-sections, if continuously cast, is an acceptable alternative to macroetching. Sulfur printing shall be performed in accordance with Practice E1180 . Examination and rating of specimens shall be in accordance with Sections 10 and 11 of this ( E381 ) standard. 4.6 Steel from ingots, in the wrought condition, shall be examined according to procedures described in Section 9 . Continuously cast steel blooms and billets, in the as cast condition, shall be examined according to the procedures described in Sections 10 and 11 . With reductions over a 3:1 area ratio, wrought product from continuously cast steel may be examined according to Section 9 . 4.7 The “R” series of photographs in Plate I shall not be used to rate Type A segregates, occasionally referred to as “carbon spots” and “sulfur segregation.” Type A segregates form in channels of the liquid-solid zone of large, solidifying ingots and appear as dark spots, including pitting due to removal of indigenous manganese sulfide microinclusions, on etched transverse sections of resultant forgings due to chemical and microinclusion content differences with the matrix. They appear as streaks in etched longitudinal sections and contain elevated levels of segregation-prone elements such as C, S, P, Si, Mn, Cr and manganese sulphide microinclusions. While Type A segregate patterns (including accompanying MnS pitting) have some similarities in appearance with the conditions in the Plate I “R” series photographs, they can be distinguished from the R series conditions because they are more symmetrically arrayed about the section center, and individual spots are typically more uniform in size at a given radius. The photographs in Annex I depict the presence of Type A segregates. The nature of questionable indications should be verified by microscopic examination or other means of inspection.