1.1本规程描述了一种基于定量金相测量对钢试样中最大原生非金属夹杂物分布进行统计表征的方法。这种做法不适合评估外源性夹杂物。 1.2基于统计分析，可以比较不同批次钢的非金属含量。 1.3本规程仅涉及推荐的试验方法，其中任何内容均不应解释为定义或确定可接受极限。 1.4测量值以国际单位制表示。 对于从光学显微镜获得的测量，线性特征参数应报告为微米，特征区域应报告为微米。 1.5该方法可以扩展到其他材料和其他微观结构特征。 1.6 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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 本规程用于评估本地夹杂物或第二种夹杂物- 使用极值统计的金属相成分。 众所周知，齿轮和轴承等机械部件的故障通常是由大量非金属氧化物夹杂物引起的。部件的故障通常可以追溯到存在大量夹杂物。根据测试方法E 45等标准提供的评估，不可能预测与部件疲劳寿命相关的结果 ，规程E 1122 ，或练习E 1245 . 一些不同的研究人员已经将极值统计的使用与部件寿命和夹杂物尺寸分布相关 (3- 8. ) . 本实践的目的是创建执行此分析的标准化方法。 由于外源夹杂物分布的不可预测性，该做法不适用于评估钢和其他金属中的外源夹杂物。必须使用超声波等涉及全面检查的其他方法来定位其存在。

1.1 This practice describes a methodology to statistically characterize the distribution of the largest indigenous nonmetallic inclusions in steel specimens based upon quantitative metallographic measurements. The practice is not suitable for assessing exogenous inclusions. 1.2 Based upon the statistical analysis, the nonmetallic content of different lots of steels can be compared. 1.3 This practice deals only with the recommended test methods and nothing in it should be construed as defining or establishing limits of acceptability. 1.4 The measured values are stated in SI units. For measurements obtained from light microscopy, linear feature parameters shall be reported as micrometers, and feature areas shall be reported as micrometers. 1.5 The methodology can be extended to other materials and to other microstructural features. 1.6 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== This practice is used to assess the indigenous inclusions or second-phase constituents in metals using extreme value statistics. It is well known that failures of mechanical components, such as gears and bearings, are often caused by the presence of large nonmetallic oxide inclusions. Failure of a component can often be traced to the presence of a large inclusion. Predictions related to component fatigue life are not possible with the evaluations provided by standards such as Test Methods E 45 , Practice E 1122 , or Practice E 1245 . The use of extreme value statistics has been related to component life and inclusion size distributions by several different investigators (3- 8 ) . The purpose of this practice is to create a standardized method of performing this analysis. This practice is not suitable for assessing the exogenous inclusions in steels and other metals because of the unpredictable nature of the distribution of exogenous inclusions. Other methods involving complete inspection such as ultrasonics must be used to locate their presence.