The formation of this zone affects the strength of the
welded joint. When the metal is thermally exposed, when structural changes occur, internal stresses are formed inside it, which may lead to the formation of micro-cracks after reaching a certain limit.
Distance in [mm] of each zone (CG-HAZ, HAZ) from
welded joint centre-line (e.g.
The above studies indicate that the various microstructure of the
welded joint is an important parameter of affecting corrosion resistance.
Every
welded joint has imperfections which cause an increase in stress amplitudes, which is implicitly considered in S-N curve [25].
In FSW the induced friction may soften the metals of the
welded joint region in a temperature less than the melted point of the metal .
2) The damage is the most severe in the
welded joint during fatigue.
Since these
welded joints are subject to various loads and fatigue during their service life, possibly giving rise to safety and quality issues, it is vital that rigorous testing and inspection procedures are applied, to examine the structure of completed welds and their conformation to specification, as well as determining the skill levels of the welding operators.
The
welded joint, prepared by using the developed acidic flux, was found to be radiographically sound.
The second method is based on the production of the
welded joint by electric arc welding with compulsory welding of the upper part of each element to be welded to the produced composite electrode and ensures melting of the metal of the
welded joint only after melting the connecting element made of the parent material.
FE model of
welded joint split to elements, and fragment of
welded joint are shown in Fig.
Welded spot arrangement will determine the development in
welded joint of different stresses for different areas of the
welded joint.