Photoelectric Direct-Reading Spectroscopy Determination of C, Si, Mn, P, S, Cr, Ni and Cu in Carbon Steel Wire Prepared by Cold Pressure Moulding

Cold pressure moulding was proposed for preparation of sample disc with diameter of 40 mm from carbon steel wire samples with external diameter less than 0.5 mm, and used for determination of C, Si, Mn, P, S, Cr, Ni and Cu by photoelectric direct-reading spectroscopy. The carbon steel wire samples (with external diameter less than 0.5 mm) were annealed in a muffle furnace at 825℃ for 30 min in Ar-atmosphere with Ar-pressure of 0.3 MPa (for low-carbon steels, the annealing was not necessary). After cooling to normal atmospheric temperature, the wire samples were polished with sandpaper to give metallic lustre, then cleaned with absolute alcohol and dried in air. The samples were cut into segments of 40 mm in length, and were placed into the aluminum cup of the cold extrusion press and well covered. Working parameters of pressure and time of the press were adjusted to definite values according to the value of tensile strength of the samples and the wire segments were treated by cold-extrusion under the mode of slow pressurization to give sample discs with diameter of 40 mm, which were suitable for use in direct-reading spectroscopy. Sample discs of carbon steel wire samples were prepared by the method mentioned above were analyzed with 3 point excitation for determination of the 8 elements, which were determined simultaneously by a checking analysis with wet analytical methods given by GB method, giving analytical results of the 8 element found by this method in good consistency with the results found by the methods of GB standards (wet analysis), showing that the proposed method of sample preparation from carbon steel wire was good in reliability and feasibility.