Typical
Cross Sections of High Frequency Welded Alloy 443
Magnified
50x - Before Annealing
Magnified
50x - After Annealing
The high frequency welding process produces a narrow, hot wrought "forge weld" structure of exceptional functional quality. The photo-micrographs above show the weld structure. The left hand photo-micrograph is in the as-welded condition. The right hand photo-micrograph is the same tube, after annealing. Note the narrow homogeneous structure of the weld and heat affected zone. The term "Fineweld" originates from the fact that the width of the heat affected zone measures approximately one-half the thickness of the tube wall. The weld is uniform from top to bottom, indicating a uniform heat energy input. Since a high frequency induction weld is a wrought structure similar to the parent material, its strength, ductility and corrosion resisting characteristics are similar to the parent material.