Study On Microstructure And Properties Of Active Flux Aided Laser Welding

Active flux aided TIG welding (A-TIG welding) has been used in stainless steel,titanium alloy material in our country since2000. The use of active flux improvedweld penetration, weld forming has been improved, and so is the productionefficiency. Laser welding has been paid more and more widely attention at home andabroad, the welding speed is high, heat affected zone is small, and the weldperformance is good. But be subjected to the laser power and cost, if need to weldrelatively thick plate, then need high laser power, which means that the high cost ofinputs.This paper takes the research object of the stainless steel, using laser weldingmethod, studying the effect of single and mixed active flux on the laser weldpenetration and organizational behavior, and by means of analysis of high-speedphotography in the changes of active flux application of laser welding plasma shape.Through the test of the semiconductor active laser welding and the active fiber laserwelding test, and analysis and discuss on different wavelengths of laser and an activeflux effect.According to the304austenitic stainless steel, by use of the laser welding andbutt welding of butt joint activity, through metallographic analysis, energy spectrumof EDS analysis and other methods, and study the rule on the effect of the coatedactive agent after304austenitic stainless steel weld penetration, depth width ratio ofweld, microstructure, chemical composition. Then get the conclusion that no mattersemiconductor laser welding or fiber laser welding, microstructure composition hasnot changed, both are austenite dendrite. The growth direction of columnar crystalmicrostructure of weld metal using the active agent in the weld fusion line directionperpendicular to each other, there is a part of isometric grains in weld center. Theactive agent in laser welding has certain effect, the existence of active agents makesthe weld penetration increase to a certain extent, including Cr2O3, SiO2, compositeactive flux respectively make the penetration increase50%,59%,75%, TiO2 increase penetration depth, which is not obvious. Changes in the melting width,Cr2O3makes the weld width increase by3%, but the weld coating three other activeflux reduces the weld width, composite active flux make the most obvious reduced inthe weld width, by decrease of11%.