1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology. Standards EVALUATION OF NON-METALLIC INCLUSION IN STEEL EDS-T-7105 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 1/11 ISSUED
2、 DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology 1. PURPOSE AND SCOPE This standard specifies the microscopic evaluation method for non-metallic inclusions in steels with the help of figure diagrams and tables. Non-metallic inclusions shall be tested according to
3、 method M and method K. 2. CONCEPTION Non-metallic inclusions may cause structure destruction in steels and affect steel properties and its form and distribution depend on melting method of steels, construction of furnace, kind and method of deoxidation and machining method. Distributions and form o
4、f inclusions, besides the quality of steels, may be learned with the average determination method according to method M and evaluation method according to method K. 3. TEST SAMPLE 3.1. Form of test sample 3.1.1. Sampling area of test pieces to be tested for each test sample (refer to Fig. 1). Dimens
5、ions (diameter or lateral length) Position of slide-surface in the test sample 25 max. Over the entire cross section(cross section including center axis) 25 50 Over the entire cross section or cross section from the edge to longitudinal axis 50 min. In the center between edge and longitudinal axis o
6、r according to the agreementFig. 1 Disk thickness Test surface Disk thickness Test surface Test surfaceDisk thickness Unit : mm METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 2/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Te
7、chnology 3.1.2. Size of test surface Method M : Minimum 150mm2Method K : Minimum 100mm23.2. Sampling and preparation of test piece 3.2.1. At the time of sampling, it shall be noticed that the kind, size, form, quantity and distribution of non-metallic inclusions depend on the kind of steels, melting
8、 and casting method(including deoxidation method), the form and the size of raw ingot and the deformation. 3.2.2. The test sample shall be taken so that its slide surface shall be in parallel with the machining direction of crystal grain and in the longitudinal side including the center of the produ
9、ct. If necessary, the position of slide-surface and sampling may be indicated in drawings. 1) This test is conducted only at approval and change in physical properties 2) Ball : Cut across the pole plane after checking the pole by soaking in 50% hydrochloric acid. 3) coil and leaf spring : cut out i
10、n the longitudinal direction (minimum length : 20 , minimum cross section : 200 ) However, for the multi-leaf spring, each leaf shall be cut out in the longitudinal direction and evaluated. 3.2.3. At the time of test piece preparation, treat the sample carefully lest original form of inclusions shou
11、ld be changed. 3.3. Number of test piece In principle, sample one test piece from one test sample. For routine quality supervision and sampling from the initial product, at least one min. of test sample is required. 4. APPARATUS 4.1. Test equipment for microscopic measurement 4.1.1. Optical microsco
12、pe with a magnification of 100X The area of measurement to be observed shall have the same optical size as that of the figure of 80 in table to be compared with it. 4.1.2. Test sample holder or mounting equipment for holding or mounting test samples. 4.1.3. Grinding and polishing equipment. 5. SUPPL
13、EMENT 5.1. Figure series table METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 3/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology 5.1.1. Series(vertical) The figure series table listed in the supplement of this test me
14、thod is composed of 10 individual figure series of inclusions with different kinds and forms. SS : Line form of sulfides(sulfide type) :2 figure series OA : Dissolved form of oxide(alumina type):3 figure series OS : Line form of oxide(silicated type) :3 figure series OG : Globular form of oxide(glob
15、ular type) :2 figure series Among these main groups, line 1, 3, 6, 8 shall be regarded as base lines, the rest are derived forms of base lines, which shall be the reference to calculate the thickness and diameter of certain inclusions. 5.1.2. Lines(horizontal) (1) The figure series table grasps, on
16、the one hand, inclusions of very small size, melted according to special method(characteristic number 0) and on the other hand, up to inclusions (characteristic number 8) with length which exceeds the sight of the microscope with a vision field of 80 under the magnification of 100 times. Characteris
17、tic number is given to inclusions of 1.5 min. under microscope and indicates the length and diameter of characteristic inclusions by corresponding average effective area determined by length and diameter to figure series table respectively. (2) Characteristics for lines 1) If listed in a line, inclu
18、sions of different kinds have the same area. 2) Area between two consecutive lines is double. 3) Different inclusions in a line have the same fine ratio(Ratio of length to width) (3) The numerical value 1 in mm under the individual vision field means the respective effective area for the length or t
19、he diameter of characteristics, nonmetallic inclusions. (4) Nonmetallic inclusions of a same size and shape shall be listed in a same figure series table. 5.2. Table 1 This table describes very small line-shaped non-metallic inclusions showing structural breaks in its total length. This table 1 list
20、s the length determined by width b and determines lines which correspond to those of figure series table and evaluate by comparison with figure series table according to area. 6. TEST METHOD 6.1. Observe the test surface under the magnification of 100 times. 6.2. All remarkable inclusions shall be o
21、bserved for testing. 6.3. Correspond inclusions of a measuring area to the pictures most similar to each in Figure series Table by comparing one another. 6.4. Interrupted inclusions METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 4/11 ISSUED DATE: 1988. 11. 10 REV
22、ISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology Thin and interrupted inclusions lying in a line shall be evaluated as follows. 6.4.1. Plastically shaped inclusion lines or spot shape inclusions without brittleness shall be regarded as connected, if the greatest interval X between two
23、component parts of a line is shorter than the component part Y regarded as the largest among lines. If interval Z is greater than the largest component part Y, this is not counted to the total length L. 6.4.2. At the determination of length of inclusions, the interval X between component parts are o
24、bserved in a same line, almost uninterrupted inclusion shall have value (length L) as component part of a line. 6.4.3. The characteristic numbers given in Table 1 represent the evaluation value to different types of inclusions(LINE 0-9). 6.5. Nonmetallic inclusions shall be evaluated according to me
25、thod M or K. 7. EVALUATION METHOD 7.1. Method M Evaluation method by determining the largest inclusion among various types of inclusion whose limited values indicated in Figure series Table according to each area. 7.2. Method K 7.2.1. The number of inclusions corresponding to a type and given size o
26、f inclusion - characteristic number(K value) shall be noted. The number of inclusions observed from the given size - characteristic factor(line) shall be multiplied with the factor fg corresponding to respective line and shall be listed in Table. 7.2.2. The resulting products according to item 7.2.1
27、 shall be separately summarized according to sulfide and oxide inclusions. This makes subtotal 1. The subtotal 1 shall be added for the entire test sample(slide surface) so that subtotal 2 is obtained. METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 5/11 ISSUED DA
28、TE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology 7.2.3. The subtotal 2 shall be multiplied with 1000 and divided by the area of tested entire slide surface and then the resulting value, regarded the sum characteristic K, shall have integral value and shall be indica
29、ted in drawings and material specification. Subtotal 2 100 Sum characteristic K = - Total slide surface area of tested sample(mm2) If indicating sulfide and oxide inclusions with the sum characteristic K, sulfide inclusions are indicated as KS and oxide inclusion as KO. 7.2.4. The sum of KS and KO w
30、hich are the sum characteristic of respectively different inclusions is the total sum characteristic K. 7.2.5. The sum characteristic KS and KO or total sum characteristic K shall be for example, indicated as K4 to indicate the smallest size - characteristic factor(n) to be tested. 7.2.6. Table 2 Si
31、ze - characteristic factor(n) 0 1 2 3 4 5 6 7 8 Factor f = 2n-4 1/16 1/8 1/4 1/2 1 2 4 8 16 Factor fg to be applied at the time of evaluation (respective factor f finished) 0.05 0.1 0.2 0.5 1 2 5 10 20 7.2.7. Example description The following examples describe the evaluation by the sum characteristi
32、c at the observation of non-metallic inclusions corresponding to size characteristic factors 4 (n 4, example 1) and size characteristic factor 1 (n 1, example 2). 7.3. Guidance in detail At the evaluation of non-metallic inclusions in pure iron following characteristic value or the sum characteristi
33、c value shall be considered. 7.3.1. Method M Unless otherwise specified in drawings or material specification for inclusions, there shall be no inclusion whose size exceeds size characteristic 4, or size characteristic number 2 in case that diameter is less than 20 . 7.3.2. Method K Unless otherwise
34、 specified in drawings or material specification, non-metallic inclusion of carburized steel or heat treated steel shall conform to the following values. Division Carburized steel Heat-treated steel Thickness or diameter of 20 50 KO 30 KO 20 Thickness or diameter of 50 130 KO 40 KO 30 METHOD OF MICR
35、OSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 6/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology Example 1. In Case Size Characteristic Factor is 4 or more, Total Sum Characteristic Sample number Area of slide surface per sample (
36、 ) Kind and form of inclusions according to figure series Number of inclusions observed per size-characteristic factor(n) Subtotal 1 and its result 0 1 2 3 4 5 6 7 8 MAIN LINE (FACTOR : fg)(0.05) (0.1) (0.2) (0.5) (1) (2) (5) (10) (20) 1 450 SS 3 1 1 - - S:10 OA 5 1 - - - OS 2 - - - - O:10 OG 1 - -
37、- - 2 400 SS 4 2 - - - S:08 OA 3 1 1 - - OS 2 1 - - - O:21 OG 2 - 1 - - 3 350 SS 2 1 - 1 - S:14 OA 4 2 - - - OS 1 1 - - - O:12 OG 1 - - - - 4 600 SS 5 - - - - S:05 OA 8 1 - - - OS 1 1 - - - O:15 OG - 1 - - - 5 250 SS 1 1 1 - - S:08 OA 3 1 - - - OS 1 - 1 - - O:14 OG 1 1 - - - 6 300 SS 4 1 - 1 - S:18
38、OA 2 2 1 - - OS 2 - 1 - - O:21 OG 1 1 - - - Sum of slide surface 2350 Subtotal 2 S:61 O:93 Sum characteristic K4 S:25 O:40 Total sum characteristic K4 S+O : 65 *) Sample number 1 S = (fg Number of sulfide) = (1 3) + (2 1) + (5 1) = 10 O = (fg Number of oxide) = (5+2+1) + (2 1) = 10 Subtotal 2 1000 9
39、3 1000 Sum characteristic KO = - = - = 39.7 = KO = 40 The area of entire slide surface 2350 METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 7/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology Example 2. In Case Size Cha
40、racteristic Factor is 1 or more Sample number Area of slide surface per sample ( ) Kind and form of inclusions according to figure series Number of inclusions observed per size-characteristic factor(n) Subtotal 1 and its result 0 1 2 3 4 5 6 7 8 MAIN LINE (FACTOR : fg)(0.05) (0.1) (0.2) (0.5) (1) (2
41、) (5) (10) (20) 1 560 SS 6 1 - - - - - - S:0.8 OA - - - - - - - - OS 1 - - - - - - - O:0.1 OG - - - - - - - - 2 530 SS 5 2 - - - - - - S:0.9 OA - - - - - - - - OS - - - - - - - - O:0 OG - - - - - - - - 3 570 SS 7 1 - - - - - - S:0.9 OA 2 - - - - - - - OS - - - - - - - - O:0.2 OG - - - - - - - - 4 60
42、0 SS 6 3 - - - - - - S:1.2 OA - - - - - - - - OS - - - - - - - - O:0 OG - 1 - - - 5 520 SS 4 - - - - - - - S:0.4 OA - - - - - - - - OS - - - - - - - - O:0 OG - - - - - - - - 6 540 SS 7 1 - - - - - - S:0.9 OA - - - - - - - - OS - - - - - - - - O:0.2 OG 1 1 - - - Sum of slide surface 3320 Subtotal 2 S
43、:5.1 O:0.5 Sum characteristic K4 S:15.4 O:1.5 Total sum characteristic K4 S+O : 17 8. OTHER ITEMS 8.1. Indication method in drawings and material specification Nonmetallic inclusions according to EDS-T-7105: KS15, KO20 8.2. Deviations according to this test conditions shall be determined through con
44、sultations and conditions shall be indicated in part drawings and material specification and shall be recorded in the form of test certificates or other METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 8/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSI
45、ON: 4 GM DAEWOO Auto & Technology written papers. 8.3. Caution for evaluation of non-metallic inclusions 8.3.1. Caution is required when drying test sample because there is a possibility of judging non-metallic inclusions as larger than actual because of corrosion or water marks that are not removed
46、 by polishing. 8.3.2. Caution is required when grinding because there is a possibility of error in judging the type of inclusions due to separation or deformation of inclusions by excessive grinding force. 8.4. Supplement Nonmetallic inclusions are indicated in Figure series Table of 30:1 in the pho
47、tograph scale. For iron steel test, Figure series Table of 100:1 in the original ratio may be used. METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 9/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology Appendix : FIGURE S
48、ERIES TABLE L : METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 10/11 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology METHOD OF MICROSCOPIC TEST FOR THE NON-METALLIC INCLUSIONS IN STEEL EDS-T-7105PAGE: 11/11 ISSUED DATE:
49、 1988. 11. 10 REVISED DATE: 2004. 12. 21 VERSION: 4 GM DAEWOO Auto & Technology TABLE 1. Width and length allocation of thin, interrupted, non-metallic inclusions occurring in a line to the rows in the illustration series. Line Identification True Width(b) of Non-metallic Inclusions in mm 0.25 0.5 1 2 3 5 7 10 Per line identificatio
