1.1 本试验方法涵盖了一种金相学方法，用于测定粉末锻造（PF）用铁粉的非金属夹杂物水平。 1.2 本试验方法涵盖了粉末锻造试样，其中材料横向流动最小(< 1. %). 粉末锻造试样的核心区域应不包含在100×。 1.3 本试验方法不适用于测定粉末锻造试样的非金属夹杂物水平，这些粉末锻造试样的核心区域含有孔隙。 在本试验方法中使用的放大倍数下，残余孔隙度很难与氧化物夹杂区分。过多的残余孔隙度使得无法对包裹体总体进行有意义的评估。 1.4 该试验方法可适用于含有硫化锰（混合或预合金）的材料，前提是近邻分离距离从30μm更改为15μm。 注1: 该试验方法可适用于提供了大量材料流的粉末锻造零件: 近邻分离距离改变，或 根据物流量调整双方约定的夹杂物尺寸。 1.5 单位- 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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、健康和环境实践，并确定监管限制的适用性。 1.7 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 压制和烧结的铁材料中存在大量孔隙，掩盖了夹杂物对机械性能的影响。相比之下，锻造至接近全密度的材料粉末的性能受到非金属夹杂物的成分、尺寸、尺寸分布和位置的强烈影响。 4.2 粉末锻钢中非金属夹杂物的测试如下所示: 4.2.1 将一级粉末与另一级粉末进行分类或区分的特征。 4.2.2 粉末锻造用粉末的质量比较方法，逐批。 4.3 如果出现以下情况，非金属夹杂物含量将发生显著变化: 4.3.1 用于形成试样的粉末不符合非金属夹杂物含量的粉末锻造质量标准。 4.3.2 粉末锻造试样的加工是在不允许氧化还原或不允许试样氧化的条件下进行的。

1.1 This test method covers a metallographic method for determining the nonmetallic inclusion level of ferrous powders intended for powder forging (PF) applications. 1.2 The test method covers repress powder forged test specimens in which there has been minimal lateral material flow (< 1 %). The core region of the powder forged test specimen shall contain no porosity detectable at 100×. 1.3 This test method is not suitable for determining the nonmetallic inclusion level of powder forged test specimens that have been forged such that the core region contains porosity. At the magnification used for this test method, residual porosity is hard to distinguish from oxide inclusions. Too much residual porosity makes a meaningful assessment of the inclusion population impossible. 1.4 The test method may be applied to materials that contain manganese sulfide (admixed or prealloyed), provided the near neighbor separation distance is changed from 30 μm to 15 μm. Note 1: The test method may be applied to powder forged parts where there has been a greater amount of material flow provided: The near neighbor separation distance is changed, or The inclusion sizes agreed between the parties are adjusted for the amount of material flow. 1.5 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 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 The extensive porosity present in pressed and sintered ferrous materials masks the effect of inclusions on mechanical properties. In contrast, the properties of material powder forged to near full density are strongly influenced by the composition, size, size distribution, and location of nonmetallic inclusions. 4.2 The test for nonmetallic inclusions in powder forged steels is useful as the following: 4.2.1 Characteristic to classify or differentiate one grade of powder from another. 4.2.2 Means of quality comparison of powders intended for powder forging, lot to lot. 4.3 Significant variations in nonmetallic inclusion content will occur if: 4.3.1 The powder used to form the test specimen does not meet powder forging quality standards for nonmetallic inclusion content. 4.3.2 Processing of the powder forged test specimen has been carried out under conditions that do not permit oxide reduction or allow oxidation of the test specimen, or both.