GB464191A - Improvements in and relating to welding - Google Patents

Abstract

464,191. Uniting by fusion. UNION CARBIDE & CARBON RESEARCH LABORATORIES, Inc. Sept. 3, 1936, No. 24105. Convention date, Nov. 5, 1935. [Class 83 (iv)] In a process of seam welding parts in line or at an angle to each other, the back of the seam or the front and back of the seam are enclosed by a thick layer of unbonded granular refractory mineral material and weld metal is deposited in and along the seam from the front side of the work parts. Electric arc welding with carbon or with bare or coated metal electrodes, or gas or alumino thermic welding may be used. The refractory material must have a melting point not substantially higher than that of the metal to be welded and must be substantially free from gas-forming ingredients. It preferably consists of silicates of alkaline earth metals and of magnesium, preferably prefused to complete chemical reactions between the ingredients. Such a prefused material may consist of 31 per cent of CaO, 11 per cent of MgO, 52 per cent of SiO2, and 4 per cent of A12O3, to which 5 per cent of an alkaline earth fluoride may be added. The work parts 10, 11, which are separated by a square or bevelled gap, rest on or are clamped to the container 13 for the refractory material 14, which may also be pressed against the work by a metal plate 18 and pneumatic tube 17. The container may be slightly longer than the seam or may be short and moved along the seam during welding. It may extend beyond the end of the weld so that a bead 16 may be formed at the end, which may be subsequently cut off flush. The refractory'material is fused during welding and a bead of welding metal is formed at the lower as well as at the upper surface of the seam. In are welding the electrode 12 may be submerged in a material 14 preferably of the same composition placed on the front of the seam, as shown in Figs. 3 and 7.