1970 Volume 39 Issue 2 Pages 138-146
Microscopic survey, measurement of grain size and electron probemicroanalysis of Fe-Al, Fe-Cr, Fe-W, Fe-V, Fe-Si, Fe-Ti Fe-Mo and Fe-Zr weld metals were performed.
The results obtained are summarized as follows:
(1) The solidification structure of Fe-Al, Fe-Cr, Fe-W, Fe-V or Fe-Si weld metals changes from equiaxed to columnar crystal with increasing contents of alloying elements.
(2) The solidification structure of Fe-Ti weld metals changes from equiaxed to columnar crystal and again to equiaxed crystal attended with the segregation of titanium.
(3) The solidification structure of Fe-Zr weld metals changes from equiaxed to cell structure and further to cellular dendrite with increasing zirconium content.
(4) The segregation of alloying element is observed on sub-boundaries of the cell structure and cellular dendrite in Fe-Zr weld metals.
(5) The solidification structure is disarranged during cooling through the γ-loop.
(6) Concentration gradients of alloying elements of 10 to l00μ width are observed.near fusion lines.
(7) The alloying elements in weld metals appear to diffuse into unmelted base metal from 5 to 10 μ.
(8) The macroscopic segregations of alloying elements are not seen in the weld metals.