1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards METHOD OF SULPHUR PRINT TEST FOR STEEL EDS-T-7106 ISSUED DATE: 1990. 08. 17 REVISED DATE: 2006. 06. 19 VERSION: 2 EDS-T-7106METHOD OF SULPHUR PRINT TEST FOR STEEL PAGE: 1/3 ISSUED DATE: 1990. 08. 17 REVISED DATE: 2006
2、. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 1. SCOPE This standard specifies the method of the sulphur print test for steel. However, steels which contain over 0.10% sulphur are excluded. This standard is suitable for steel castings. 2. DEFINITION 2.1. Sulphur print test A method for investigati
3、ng the distribution of sulphide in a steel by means of the sulphur print obtained by putting a photographic paper previously soaked in the sulphuric acid solution, closely on a section of the steel. 3. TEST PIECE The flat test piece shall be cut from the forged or rolled steel generally in perpendic
4、ular direction to the working axis. However, hot shearing will affect to alignment of inclusion and texture segregation, etc. and gas cutting will cause hardening or crack, it is appropriate to take the test piece apart from these portions. After cutting and grinding, the test surface of the test pi
5、ece shall generally be free from grease prior to the test. 4. TEST METHOD 4.1. Use the photographic paper for the sulphur print test. 4.2. Immerse the photographic paper which has been cut to dimensions appropriate to the test surface in 1 - 5% sulphuric acid solution, and soak it with the solution
6、sufficiently(approximately for 5 minutes). Then, remove the excess solution by putting it between papers or using the absorbent cotton or the like after taking it out from the solution. 4.3. Immediately, adhere the photographic paper which has been removed the solution sufficiently over the entire t
7、est surface, and then, remove the air bubbles by pressing with the absorbent cotton to prevent the photographic paper from slipping off. After enough time to enable the coloring of the photographic paper to a suitable density by reacting with the sulphide contained in the steel, take off the photogr
8、aphic paper from the test surface. In this case, the adhering time of the photographic paper shall be about 1 - 3 minutes. 4.4. Wash the photographic paper which has been taken off from the test surface and immerse it in 15 - 40% aqueous solution of at room temperature for 5 - 10 minutes. After fixi
9、ng with the solution, wash it with running water for 30 minutes or more. 4.5. After fixing and washing, examine the state of distribution of the sulphide with respect to the dry photographic paper. EDS-T-7106METHOD OF SULPHUR PRINT TEST FOR STEEL PAGE: 2/3 ISSUED DATE: 1990. 08. 17 REVISED DATE: 200
10、6. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 4.6. Where the same test surface is to be tested again, cut off the test surface until the effect of previous test disappears. 5. CLASSIFICATION OF TEST RESULT 5.1. In the sulphur print test, the classifications and symbols of the state of the distrib
11、ution of sulphur shall conform to Table 1. Furthermore, examples of photographs shall be indicated in Attached Figure. Classfication Symbol Remark Normal segregation SNA type of segregation normally observed on common steel. Sulphide distribution increases from periphery towards center of the steel,
12、 where the coloration on the photographic paper presents darker in the center than that of the periphery. The coloration is particularly lighter in the rim part of rimmed steel. Inverse segregation SIA type of segregation in which the sulphide distribution decreases from periphery towards center, wh
13、ere the coloration on the photographic paper presents lighter in the center than that of the periphery. Central segregation SCA type of segregation in which sulphide distribution is concentrated at the centre of the steel, where particularly dense coloration on the photographic paper being presented
14、. Dispersed segregation SDA type of segregation, in which the segregations of sulphide are presented in densely coloured spots on the photographic paper. Linear segregation SLA type of segregation, in which the segregations of sulphide are presented in densely coloured lines on the photographic pape
15、r. Columnar central segregation SCOA type of segregation as observed in steel section and the like, where the central segregation presents in a columnar shape on the photographic paper. 5.2. In the case where the test results of the sulphur print test are to be indicated, these shall be indicated wi
16、th the symbols of 5.1 respectively. Example: SN-SD : A normal segregation, and in addition, a dispersed segregation is also observed. 6. REFERENCE JIS G 0560 Method of sulphur print test for steel EDS-T-7106METHOD OF SULPHUR PRINT TEST FOR STEEL PAGE: 3/3 ISSUED DATE: 1990. 08. 17 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology Attached Figure. Example for Classification of Sulphur Print
