GB1021923A - Process of electrical welding by fusion - Google Patents

Abstract

In submerged arc or electroslag welding, a tubular electrode containing a basic flux introduces basic constituents to the melt which is composed in such a way that the resultant fused slag is non-basic i.e., has a basicity index less than 1.4, the basicity index being the ratio B/A where B equals weight of CaO+MgO +BaO+K2O+Na2O+Li2O+CaF2+ 1/2 MnO and A equals SiO2+ 1/2 (AleO3+TiO2, +ZrO2). In submerged arc welding steel plates, a tubular steel electrode having a core of basic flux comprising .6-11% low carbon ferromanganese. ..(80% Mn, 1% C) .30-50%.CaF2 .10-18%.MnO .0-16%.SiO2 .10-30%.CaO+MgO .1- 2%.silicomanganese ..(25% Si, 74% Mn, 1% C) .0-6%.miscellaneous was used with the following acid-type granular flux .45-65%.SiO2 .0- 6%.Al2O3 .30-50%.MnO .0- 4%.miscellaneous To obtain a fully deoxidized weld having a carbon content less than 0.05%, oxidizers are added to the basic core of the electrode to decarburize the weld metal, and deoxidizers are added to the granular flux to deoxidize the decarburized weld metal. A plurality of tubular electrodes with basic cores may be used, the leading electrode containing oxidizers such as iron oxide and the trailing electrode(s) containing alloying elements including manganese and deoxidizers e.g. aluminium, ferrosilicon, carbonless ferrotitanium and ferromanganese. In electroslag welding, the electrode is tubular with a basic core containing deoxidizers e.g. ferrosilicon, ferrotitanium, silicomanganese or ferromanganese and the flux is a flux such as .45%.SiO2 .3%.Al2O3 .5%.CaF2 .35%.MnO .4%.MgO .5%.CaO .3%.miscellaneous rendered highly oxidizing by treating with oxygen in an electric furnace to increase its oxygen content to 49%.