Estimation of the heat-affected zone for the electron-beam welding of plates

We describe a procedure and present some experimental results of evaluation of the heat-affected zone (HAZ) for butt electron-beam welding of the plates of variable thickness with regard for the nonuniform distribution of energy. It is shown that the heat removal caused by the increase in the thicknesses of the plates leads to changes in the sizes of the HAZ in the upper part of the welded joint. It is established that the instantaneous cooling rate changes with the distance from the reference point as a result of changes in the rate of energy input, which is responsible for the inhomogeneity of the microstructure over the thickness of the joint.