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The submerged arc welding machine is used for the drum welding. Ensure accurate welding procedures and welding processes, accurate and stable line energy, eliminate unfused and incomplete penetration, and minimize the occurrence of slag inclusions, pores and cracks. The shape coefficient of the weld is good, the surface of the weld bead is smooth, the pass rate of welding is high, the weld is beautiful, and the welding quality is high.