Lance tip esp. for steel converter oxygen@ lance

摘要

A Cu (alloy) tip (5) for a water-cooled metallurgical lance, esp. for blowing oxygen into molten pig iron, has (a) a coating of spherical refractory metal particles of diameter (D) 0.2-3 mm and spacing 1.2D to 1.5D between their geometric centres, on its outer surface sp. in the region of each nozzle outlet opening; and (b) a uniform matt relief on its water cooled inner surface. The relief has a roughness in the nozzle/end face junction regions which is 1-2 Ra classes higher than that on the side faces and the end face, the roughness (Ra) in the nozzle/end face junction regions lying within the limits of one class and corresponding to the relationship dRai/rmin = a constant. dRa = the difference between the greatest and smallest roughness values of the relief and rmin = smallest radius of curvature of a surface in these regions.