GB878494A - Apparatus and method for making high tensile strapping - Google Patents

Abstract

878,494. Annealing. SHARON STEEL CORPORATION. June 25, 1958 [Sept. 26, 1957], No. 20438/58. Class 72 [Also in Group XII] A method of producing steel strip comprises longitudinally slitting cold rolled steel band into a plurality of strips of the required width, heating the strips in a controlled atmosphere to above the c r i t i c a 1 temperature, quenching the strips in a molten lead bath at a temperature of 900-1100‹F. and air cooling and coiling the strips. As shown, the steel strips 20, after slitting, are fed through a device 24 comprising carborundum strips to remove burrs formed during slitting, through the top of a cooling tower 37 where they are preheated by the hot treated strips, and into a furnace 24 where the temperature is raised to above the critical temperature. The furnace comprises series of tubes 50 and reversing drum 58, the strips passing first in one direction and then in opposite direction. The heated strips then enter a molten lead bath 96, having heating and cooling tubes arranged alternately transversely therof to control the temperature, and out through a box 104, filled with coke breeze into the cooling tower 37. When cooled to 180‹F. the strips pass through a paint bath 121, a straightener 133, an electronic control 150 to bridle rolls 144, 145 which draw the strips through the apparatus, and finally to coiler 148, 148<SP>1</SP>. The furnace and reversing drum chamber may be filled with controlled atmosphere and the cold, painted, strips may be given a coating of wax in a waxer 151.