ASTM E2142-08

This test method is established to cover automated SEM/EDX-based procedures for:

Rating the inclusion content of steels based on procedures listed in Standards E 45 and E 1245, with the significant difference that the composition of the individual inclusions, as determined by X-ray analysis, is utilized to sort them into chemical classes.

Determining the number, size and morphological distribution of inclusions in steels sorted by chemical class.

Methods 1 and 2 of this test method are primarily intended for rating the inclusion content of steels deoxidized with silicon or aluminum, both silicon and aluminum, or vacuum-treated steels without either silicon or aluminum additions. Guidelines are provided to rate inclusions in steel treated with rare earth additions or calcium-bearing compounds (13.4). When such steels are evaluated, the test report should describe the nature of the inclusions rated according to each inclusion category (A, B, C, D).

Methods 1 and 2 will provide a quantitative rating of the inclusion content in half-severity number increments from 0 to 5 for each inclusion type and thickness (Method D of Test Method E 45), and in tabulated in Table 2. Test Method E 45 ratings by SEM may differ from those determined following E 45 because of the use of chemistry in the classifications. In order to differentiate E 45 ratings obtained using the SEM from traditional ratings using light microscopy, the ratings obtained using Method 1 or 2 of this Test Method shall be identified as E 45-SEM1 and E 45-SEM2, respectively.

Method 3 defines procedures to analyze and report inclusions by arbitrary size distribution and chemical classifications. It may be made applicable to any material by appropriate choice of these classifications.

Method 3 determines and reports basic (as used in Test Method E 1245) stereological measurements (for example, volume fraction of sulfides and oxides, the number of sulfides or oxides per square millimeter, and so forth). This test method, however, does not address the measurement of such parameters. E 45 ratings are not produced in Method 3 because the inclusion classifications do not follow those defined in Test Method E 45.

The quantitative results are intended to provide a description of the types and amounts of inclusions in a heat of steel. This test method contains no guidelines for such use.

TABLE 2 Minimum Values for Inclusion Severity Rating Levels for Measurements in Micrometers (For expression in other units, see Test Methods E 45, Table 2)

1.1 This test method covers procedures to obtain particle size distribution, chemical classification, and Test Methods E 45 ratings of inclusions in steels using an automated scanning electron microscope (SEM) with X-ray analysis and automatic image analysis capabilities.

1.2 There are three discrete methods described. Method 1 is the SEM analog of Test Method E 45, which uses image analysis and light microscopy to produce automated Test Methods E 45 ratings. Method 2 produces similar ratings based predominantly on sorting inclusions by chemistry into the traditional classes defined in Test Methods E 45. Method 3 is recommended when explicit detail is needed on particular inclusion types, not necessarily defined in Test Methods E 45, such as to verify the composition of inclusions in inclusion-engineered steel. Method 3 reports stereological parameters such as volume or number fraction, rather than Test Methods E 45 type ratings.

1.3 This test method deals only with the recommended test methods and nothing in it should be construed as defining or establishing limits of acceptability for any grade of steel or other alloy where the method is appropriate.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory limitations prior to use.