Shielded metal arc welding

About: Shielded metal arc welding is a research topic. Over the lifetime, 4462 publications have been published within this topic receiving 40560 citations. The topic is also known as: manual metal arc welding & flux shielded arc welding.

Ac tig welding apparatus using hot wire

Abstract: An unconsumable electrode such as tungsten is opposingly arranged with a base metal to be welded. An AC arc welding power supply is connected between the base metal and the unconsumable electrode. A filler wire such as of aluminum is fed by a wire feeder toward an arc-generated part between the base metal and the unconsumable electrode. Also included is a wire-heating power supply for producing a pulsed current. The wire heating power supply heats the filler wire by supplying thereto a pulsed current in accordance with a sync signal from the AC arc welding power supply or a detection signal of an arc current i A or an arc voltage of the AC arc power supply. The filler wire is thus heated by being supplied with a heating current i W in pulse form while the unconsumable electrode is kept negative by an AC arc formed between the unconsumable electrode and the base metal. During the period when the unconsumable electrode is kept positive by the AC arc, the filler wire is not supplied with any current or is heated by being supplied only with a sufficiently small current not to cause any substantial magnetic flow. Accordingly, even if a large current flows through the wire, arc interruptions can be eliminated, thereby improving the welding process of aluminum by using an AC TIG arc.

Solidification and microstructural characterisation of iron―chromium based hardfaced coatings deposited by SMAW and electric arc spraying

Abstract: The microstructure and solidification of shielded metal arc welding (SMAW) hardfaced Fe–Cr–C deposits used in the sugar industry as well as electric arc-sprayed Fe–Cr–B coating have been determined using a combination of optical microscopy, image analysis, SEM and XRD. The aim of this study was to examine the morphology, microstructure and chemical composition of the coating. The weld microstructures consisted primarily of (Fe,Cr,Mn) 7 C 3 carbides, austenite (γ) and ferrite (α), while the arc-sprayed coating was composed of two metallic phases, α (Fe,Cr) and Fe 1.1 Cr 0.9 B 0.9 , which were intermingled with oxides of iron and chromium. The highest average hardness (850 kgf/mm 2 ) occurred in weld coating A80, compared to the 730 kgf/mm 2 measured in the arc-sprayed coating. The results of the study also showed that different welding electrodes as well as weld procedure variation produced significant differences in the morphology of the carbides, structure of the deposit and microhardness. Although the microhardness of the welded deposits was higher than the arc-sprayed coating, the arc-sprayed coating exhibited a more consistent hardness value. Porosity and oxide inclusions were more evident in the arc-sprayed coating: 1% and 3% in the weld coatings S80 and A80, respectively, and 6.5% in the arc-sprayed coating. The implications of the result with respect to solidification and microstructure are discussed.

Flux cored arc welding electrode

Abstract: A flux cored arc welding electrode of the type used with external shielding gas wherein the electrode comprises an outer ferrous sheath and a particulate fill material comprising an acidic flux system and alloying agents with the fill material including an arc stabilizer, titanium dioxide, calcium fluoride, an alloying system of 0-4.0 percent by weight of electrode selected from the class consisting of aluminum, silicon, titanium, carbon and manganese. Iron powder controls the percentage of the fill of the electrode and 0.2-1.0 percent by weight of electrode is polytetrafluoroethylene powder.

Tubular welding electrode

Abstract: A formulation for the flux in a cored-type electric arc welding electrode which produces high impact value welds while welding vertically up or overhead and at greater melt-off rates than heretofore. The major flux ingredients are lithium oxide, iron oxide, silicon dioxide, lithium carbonate, magnesium and aluminum metal powders, all in a carefully balanced formula to give excellent operator appeal and excellent slag removal.