DEVELOPMENT OF FLUXES FOR SUBMERGED ARC WELDING OF STAINLESS STEEL

Abstract

Submerged are welding is used for joining many ferrous and nonferrous metals and alloys. It is also used to apply claddings to the base metals to provide corrosion resistance i or other properties. The general classes of base metal welded are : Carbon steels upto 0.29% C and Heat Treated Carbon Steel (normalized or quenched and tempered) ; Low alloy steels, quenched and tempered (upto 10,000 p. s.l. yield strength); Chromiu..tiolybledonum steels (0.5 9•. Cr, 0.5 — 1.0% ;.io); Austenitic Chromium nickel stainless steels; Nickel and Nickel alloys (solid solution typos). The alloy composition that can ho welded in the above classes, depend on availability of suitable electrode and fluxes. In submerged arc welding,, the end of a continuous bare wire electrode is insertod into a mound of flux that covers the area or joint to be welded. An are is ini ated, causing the base metal, electrode and flux in the immediate vicinity to molt. The melted base metal and filler rte tal flow together to form a molten pool in the joint. At the same time melted flux floats to the surface to form a protective slag cover. This process is very much versatile in nature. The various properties and functions of the flux make it possible to employ the high welding currents for which the process is noted. Butt joints in thickneroses upto approximately 19 mm (3/4 in.) can be made by subzorged arc welding in a single pass with two electrodes. Joint design may vary from square groove to relatively small V grooves, smaller than those used in shielded metal arc welding. Power source can be of d.c. or a.c. types. D.C. powor source is used for all welds