G-TECH 99

Pure nickel type for welding cast iron.

Austenitic nickel with finely distributed graphite.

Grey iron.
EN W.Nr.: 1561:2011 Grey cast irons+
ASTM: A159, A319, A126, A48.

Welding is commonly performed without preheat, although scenarios involving heavy multipass deposits or highly restrained joints may necessitate preheat, potentially reaching up to 150°C. Before initiating the welding process, it is crucial to prepare surfaces meticulously, employing careful gouging and/or grinding with limited heat application to prevent the propagation of cracks. The designated welding area should be cleaned diligently, removing contaminants such as sand, oil, grease, paint, or rust to the greatest extent possible. Preheating proves advantageous for eliminating impregnated oil on used castings undergoing repairs. In instances where welding is conducted without preheat, it is advisable to minimize the width of the Heat-Affected Zone (HAZ) by utilizing a low heat input and maintaining a low interpass temperature. The application of a skip welding technique can be beneficial in achieving this objective. For welds involving thicker sections or highly restrained conditions, preheat up to 150°C may become imperative. Light peening, aimed at reducing contraction stresses, can offer additional benefits, though caution is warranted to prevent the depletion of weld metal ductility. Buttering the joint faces or the sides of the repair cavity before the filling process can be a desirable practice, whether or not preheat is applied. Upon completion of the welding process, it is recommended to allow the workpiece to cool gradually, with the option of using insulation if deemed necessary for optimal results.