Effect of Deformation Resistance of Steel on Material Flow in Friction Stir Welding – <i>In-situ</i> Observation by X-ray Radiography –

Abstract

Synopsis : Materialflowofsteelswithdifferentcompositioninfrictionstirwelding(FSW)wasdirectlyinvestigatedbyx-rayradiography.Thethree-di-mensionalflowpatternsinvariousFSWconditionswereobtainedusingtwopairsofx-raytransmissionreal-timeimagingsystems.Itrevealed thatthematerialflowpatternandtheflowrateweretightlyconnectedtothedeformationresistanceofthesteelatprocesstemperature.The materialflowzoneofthesteelwithhighercarboncontent,whichhashigherdeformationresistance,wasnarrower,anditsflowratewaslower thanthoseofthesteelwithlowercarboncontent.Theshapeofthematerialflowzonearoundtherotatingtoolwaschangedfromconcentric toellipseduetothestagnationofthematerialflowonadvancingside(AS)instirzone(SZ)undertheinsufficientheat-inputFSWcondition. Furtherdecrementoftheheat-inputinFSWledtothedefectonASinSZ.TheobtainedrelationshipbetweentheFSWconditionsandtheflow pattern showed that the lower travel speed of the tool is effective to keep the concentric shape so as not to form the defect for the steel with highercarboncontent.

Parametric effect on dissimilar friction stir welded steel-magnesium alloys joints: a review

“…In Figure 12 (a) it can be clearly seen that there is more AISI 1008 deformed phase than AISI 1078 deformed phase in the stir zone (SZ) region at rotatory speed 450 rpm. This was also given by Morisada et al [116].…”

Friction Stir Welding of Medium Carbon Steel with Laser-Preheating

“…15(b). 22) The same tendency was recognized on the angular velocity. The angular velocity rate of the material flow to the tool rotation speed of 300 rpm has increased to approximately 30% when preheating occurs at the welding center and on the retreating side, while the angular velocity rate is approximately 10% when preheating is not conducted and occurs on the advancing side.…”

“…ing the conventional FSW of medium carbon steel is about 10%. 17,22) These results indicate that laser preheating at the welding center and on the retreating side is more effective to obtain sufficient material flow. Regarding this material flow behavior during the conventional FSW, sufficient material flow region is formed on both the advancing side and the retreating side during the FSW of aluminum alloy whose heat conductivity is higher than that of carbon steel.…”

“…In this study, the difference of material flow behavior in case of each preheating position was compared from material flow velocity during the FSW evaluated by calculating the moving velocity of the tracer. 22) Average velocity of material flow during FSW with or without laser preheating is shown in Fig. 15(a).…”

High speed X-ray observation of digital controlled submerged arc welding phenomena

“…The distance from the image intensifier to the target was about 450 mm. The schematic illustration of image intensifier is shown in Figure 1(c) [27]. When the X-ray is received by the input phosphor, according to its intensity the electron is irradiated.…”