SAE J 422-1983 Microscopic Determination of Inclusions in Steels《显微测定钢中的杂质》.pdf

1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro

2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (412) 772-8512 FAX: (412) 776-0243TO PLACE A DOCUMENT

3、 ORDER; (412) 776-4970 FAX: (412) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1983 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICEAn American National StandardJ422REV.DEC83Issued 1941

4、01Revised 1983-12Superseding J422 JUN79MICROSCOPIC DETERMINATION OF INCLUSIONS IN STEELSForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat.1. ScopeThis recommended microscopic practice for evaluating the inclusion content in steel has beendev

5、eloped as a practical method of quantitatively determining the degree of cleanliness of steel. This methodhas been established as a reasonable control for steel mill operations and acceptance for productionmanufacturing. It has been widely accepted for carbon and alloy steel bars, billets, and slabs

6、 Exceptions areresulfurized grades which are outside the limits of these photomicrographs and the high carbon bearing qualitysteels which are generally classified using ASTM E 45-60T, Method A, Jernkontoret Charts.2. ReferencesThere are no referenced publications specified herein.3. Preparation of

7、SamplesThis microscopic method is based on examination of specimens approximately160 mm2 (1/4 in2) in area 10 x 19 mm (3/8 x 3/4 in). The exact dimensions are not of prime importance sincethe area examined represents an extremely small part of the bar, billet, or heat being evaluated. For bars40mm (

8、1-1/2 in) and smaller, the face obtained by cutting from surface to center with the short dimensionparallel to the rolling direction is polished and examined. If one-half the diameter is more than 25 mm (1 in),the specimen shall be taken midway between the outside and center. The manner of cutting a

9、 specimen froma 38 mm (1-1/2 in) round bar is shown in Fig. 1. A disk, 10 mm (3/8 in) in thickness should be sliced from thebar, the section indicated in Fig. 1 cut out of the disk and the shaded area polished parallel to the direction ofrolling.Bars and billets over 100150 mm (46 in) are normally f

10、orged to 100 mm (4 in) square before specimens areobtained from a midway position as described above for bars over 50 mm (2 in). This is illustrated in Fig. 2.The area that shall be polished is shown shaded and extends 10 mm (3/8 in) parallel to the length of the bar orbillet and 19 mm (3/4 in) in t

11、he longitudinal center plane normal to the longitudinal axis, so that the polishedface is midway between the outside and center of the bar or billet.It is generally desirable to facilitate polishing by hardening the specimen. Polishing may be done by anydesired technique. One generally followed is:S

12、tep 1Grind.Step 2Rough polish, going successively from Nos. 240, 320, 400 grits and Nos. 0, 00, and 000 emerypapers.SAE J422 Revised DEC83-2-Step 3Fine polish, employing some medium such as alumina or other powders having a uniform particle sizeof 0.3 m to less than 0.1 m.Step 4Wash in hot water and

13、 follow by rinsing in alcohol.Polishing scratches in the direction of rolling tends to confuse the appearance of the specimen. It is of utmostimportance that the polished surface not be pitted or the inclusions distorted.The entire polished surface of the prepared specimen is examined at 100 diamete

14、rs. The examination may bemade using the eyepiece or by projecting the field on a ground glass screen. In practice, visual observation ofthe prepared sample is often used to locate critical areas for microscopic examination.FIGURE 1SPECIMEN FROM 33 mm (1-1/2 in) ROUND SECTION FOR MICROSCOPIC TESTSAE

15、 J422 Revised DEC83-3-FIGURE 2SPECIMEN FROM LARGE BAR OR BILLET FOR MICROSCOPIC TEST4. ClassificationThe inclusions observed are compared with the accompanying series of photomicrographs ofoxides and silicates classified from 1 to 8 inclusive. The length of the field shown is represented as 1.1 mm(0

16、045 in), and the classification is based on length with consideration given to width in the photomicrographsover class 6. The maximum length of each type of inclusion oxide or silicate, is generally used to evaluate aspecimen. The silicate photomicrographs are used for all slag or fluid type inclus

17、ions and the oxidephotomicrographs for all oxide or hard type inclusions. For example, a specimen may be classified 5-0 (oxide)4-S (silicate) to indicate that the longest oxide inclusion noted was comparable to photomicrograph 5 and thelongest silicate inclusion noted was comparable to photomicrogra

18、ph 4.Modifications may be used such as suffix numerals to indicate the number of long inclusions noted or the exactlength of a particular inclusion in thousandths of an inch when over the maximum length indicated by thephotomicrographs.In evaluating steel cleanliness it is important to recognize tha

19、t the value obtained applies directly to that areabeing examined. For proper inclusion determination, adequate sampling is of prime importance. Inclusionsvary from heat to heat, ingot to ingot, and in different portions of the same ingot product. The accompanyingstandard series of photomicrographs i

20、s designed for use in evaluating the severity of the most common typesof inclusions and it should be recognized that they do not represent a complete metallographic study of steelcleanliness.SAE J422 Revised DEC83-4-SAE J422 Revised DEC83-5-SAE J422 Revised DEC83-6-5. Notes5.1 Marginal IndiciaThe ch

21、ange bar (l) located in the left margin is for the convenience of the user in locatingareas where technical revisions have been made to the previous issue of the report. An (R) symbol to the leftof the document title indicates a complete revision of the report.PREPARED BY THE SAE IRON AND STEEL TECH

22、NICAL COMMITTEESAE J422 Revised DEC83RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis recommended microscopic practice for evaluating the inclusion content in steel has beendeveloped as a practical method of quantitatively determining the degree of c

23、leanliness of steel. Thismethod has been established as a reasonable control for steel mill operations and acceptance forproduction manufacturing. It has been widely accepted for carbon and alloy steel bars, billets, and slabs.Exceptions are resulfurized grades which are outside the limits of these photomicrographs and the highcarbon bearing quality steels which are generally classified using ASTM E 45-60T, Method A,Jernkontoret Charts.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Iron and Steel Technical Committee