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Research On The Welding Operation Performance Of Submerged Arc Welding Flux-cored Wire Based On Analysator Hannover

Posted on:2017-05-18Degree:MasterType:Thesis
Country:ChinaCandidate:S W WeiFull Text:PDF
GTID:2321330509452821Subject:Materials Science and Engineering
Abstract/Summary:PDF Full Text Request
Submerged arc welding flux-cored wire is widely used in large ships, pipe butt, plunger, roll surfacing and other fields because of the improvement of technology and excellent properties. But few researches were carried out about the performance of submerged arc welding flux-cored wire. It detracts from further improving the welding operation performance of submerged arc welding flux-cored wire, the rational welding processing parameters setting and practical application. Therefore, it is very important for the research of the welding operation performance of submerged arc welding flux-cored wire by some suitable analysis methods.2Cr13 flux-cored wire was investigated in this paper and compared 2Cr13 solid welding wire, the effect of welding condition on hardness, impact toughness and microstructure of deposited metal was studied. The droplet transfer and arc stability of flux-cored wire and solid welding wire were investigated and judged by Analysator Hannover and high speed camera. After the observation of slag covering ability, the slag detachability of the flux-cored wire and the solid welding was tested by homemade falling ball machine. The samples in different submerged arc welding condition were separated, and then the mechanical properties and microstructure was investigated with brinell hardness tester, sharpy tester and optical microscope.The results showed that droplet transfer of flux-cored wire and solid welding wire were flux wall guided transfer form judged by Analysator Hannover and high speed camera. Compared with solid welding wire, flux-cored wire showed arc stability, slag detachability and slag covering ability at the welding condition of 45V/300 A and 34V/450 A. The hardness and impact toughness increase first and then decrease in deposited metal of the flux-cored wire, average percentage were at respectively 1.3% and 45% when the welding condition varied from 45V/300 A to 42V/550 A. At the same time, the hardness and impact toughness of solid welding wire deposited metal decreased, with the average percentage at 2.7% and 77.8%. The deposited metal of flux-cored wire and solid welding wire both remained relatively high hardness and impact toughness, which were separately at 429HBW/70 J and 400HBW/54 J when the welding condition were 30V/400 A and 41V/450 A. The average hardness and impact toughness of flux-cored wire deposited metal are increased by 15.6% and 49.2% separately than that of solid welding wire, which was the same with the results of Analysator Hannover. The optimum welding processing parameters of the submerged arc welding flux-cored wire are: welding speed at 35cm/min, wire extension at 40 mm, arc voltage and welding current at 31V/450 A. The microstructure of deposited metal was tempered martensite, a small amount of ferrite and troostite.
Keywords/Search Tags:Submerged arc welding flux-cored wire, Welding operation performance, Droplet transfer, Arc stability, Slag detachability
PDF Full Text Request
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