METHOD OF MANUFACTURING FOR WELDING CERAMIC BACK-UP MATERIAL

摘要

PURPOSE: A welding ceramic back-up material is provided which is adhered to the back side of steel plates at the welding portion when performing welding between the steel plates to prevent scattering or flowing of welding materials and melt a preform and a welding rod on the back side of the welding portion to form a long and thin bead. CONSTITUTION: The method for manufacturing a welding ceramic back-up material(1) comprises the steps of:mixing 89-92 wt.% of material powder of 250-350 mesh with 8-11 wt.% of water to obtain 1-2 mm diameters of granules, the material powder comprising 34-40 wt.% of alumina, 10-14 wt.% of magnesium oxide and silica for the remainder; firing the formed member obtained by pressing the granules, until the sintering step; and immersing the fired member in a silicon water repellent or a diluted sodium silicate solution to dry the fired member.