Plastic Metal Flow Behavior And Microstructure For Rotating Friction Welding

The friction welding of45steel in which the tracing materials of the wire wereinserted was carried out by using different kinds of friction welding method. Afterwelding, the metallographic samples were cut in two ways, that is, along the planesparalleled to top surface in the weld and the plane perpendicular to the weld. Theinfluence of parameters on the plastic flow of the weld metal was analyzed accordingto the distribution of tracing materials. It is comprehended that the method of weldplastic metal according to experimental observations, and carried on a comparison tothe weld metal plastic flow behavior of two kinds of frictions welding, summariedboth of common and different.The results shown that, weld plastic deformation layer formed in distance oftwo-thirds radius at first, gradually expand in a circular circle, until forming thewhole welding face, then gradually expansion in axial. The weld metal along theradial flow, weld metal will overall reverse in joint interface. As the weldingparameters of welding time, friction pressure and top forging pressure such as radialflow increased, the distance and the overall reverse gradually increased.With theincrease of weld center distance, distance and weld metal overall torsional graduallydecrease.The flow of weld metal is composed of radial flow, spiral flow and axial flow ininertial friction welding process. Along with the rotation speed and friction pressureincreases, radial flow of plastic metal gradually increase, spiral flow also increasedgradually. As the distance from the seam center increases, the radial flow of weldplastic metal decreased gradually, whole torsional angle also smaller. The weld metalmutual infiltration on the weld during the welding process, it will occur in the axialflow formed by weld metal, axial flow is increased with welding parameters.Weld metal produced plastic deformation in the process of plastic, it will occurrecrystallization phenomenon progressively refined grains. weld microstructurechange a lot along the radial, weld center for pearlite and pointlike ferrite organization,weld crater for pearlite and massive ferrite organization, ferritic grain gradually growup from weld crater to weld center. Weld microstructure also can have big changealong the axial, weld organization gradually thinning from weld center to weldaffected zone, pearlite and ferritic crystallite size gradually decrease, the ferrite is the distribution of pearlite plaque-forming in the weld center and the distribution of blockin heat affected zone.