Improvement of technological and sanitary-hygienic characteristics of gas-shielded arc welding process

Abstract

Cored wires are used in numerous welding processes with or without external gas or flux shielding. Submerged arc welding (SAW) with cored wires, seamed or seamless, for joining mild and low alloyed steel grades is a technique that has demonstrated clear advantages during the three last decades. Ever since its invention, the SAW process has evolved with one main goal: to combine quality with productivity. With low alloy wires, the benefits have already been clearly demonstrated and widely exploited. However, little has been written on SAW and cladding with cored wires for corrosion or heat resisting applications. Its extension to high alloy compositions brings corresponding benefits and adds some specific and unique features. This paper focuses on consumable specificities and on the quality and productivity features of SAW with CRA (corrosion resistant alloy) cored wires. It describes the potential as well as the limitations of this technique. Cored wires are now used for submerged arc welding of almost all stainless steels ranging from soft martensitic to super-duplex, and for a series of nickel base compositions as well as for cladding cobalt base alloys. Examples of industrial applications with austenitic, duplex, martensitic and heat resisting stainless steels are given to illustrate the potential of the cored wire solution. 13 Ref., 4 Tables , 25 Figures.

Development of Self-Shielded Flux-Cored Wires for Arc Welding of Low-Alloy Steels

“…Thus, the obtained data evidence that to ensure the high efficiency of gas shielding during welding with self-shielding flux-cored wires it is important not only to ensure the generation of a large amount of shielding gases, but also to control the processes of gas evolution to create a protective atmosphere at all stages of heating and melting of the flux-cored wire, electrode metal transfer and weld pool formation. The heat losses for heating and melting of powder core can significantly affect the welding and technological properties of the flux-cored wire [7,8]. The evaluation of these losses can be carried out using the data of differential scanning calorimetry on the example of charges of flux-cored wires of carbonate-fluorite type containing lithium carbonate (Fig.…”