Evaluation of the quality of surface hardening welds for rock ladderpipes of direct reduction unit storage tanks in steel industries

In this research, the evaluation of the quality of hardfacing welds was done by the fusionwelding process for rock ladder in the middle part of the sponge iron storage tank.Ideally, it would be great. Therefore, the following results were determined, it wasobserved that the amount of carbon in the welding surface is ۴.۶%, which has achieved acompletely martensitic structure, and the range of hardness of the hardened layer wasHRC ۶۱ to ۶۳. The amount of chromium on the surface of the hard layer was about ۲۸%,which the sources showed, including the typical microstructures of hard facing alloys ofchromium-rich layers of the eutectic type. The matrix with chromium of M۷C۳ typecarbides was visible in the surface layer of medium size chromium carbides. The brittleeffect of deposited carbide during cooling below the solubility limit could be reduced byreducing the amount of carbon. In order to confirm the welds, the manual items shouldbe considered, longitudinal cracks are not acceptable and wide cracks (gaps) should notoccur, the cracks should not continue in the base metal, and the cracks should be paralleland with approximately equal distances from each other. To get the quality of a suitablelevel. Also, the welding bands should overlap and overlap each other. The weld metalmust be completely mixed with the base metal

کلیدواژه ها:

Storage Tank ، Surface Hardness ، HARDFACING ، Chrome Carbide ، Quality Control ، Cracks.