Welding cast iron demands some special procedure. It is just a challenging task and there can be no two opinions about that. Cast iron, unlike most other steels, has much better carbon articles at 2 to 4 per-cent. This causes almost all cast iron to come to be brittle rendering it difficult to weld. If the following technique is followed, cast iron can be welded with relative ease:
Employ either cooling or heating while welding cast iron since it is important to keep casting iron from the 150- to 500-education F range. Preheating is commonly preferred, but periodically cooling are also done. ลวดเชื่อมเหล็กหล่อ But stick to either cooling or heating , nor attempt to change in the center of a weld.
Though preheating the cast ironing portion should suffice, it really is preferable to preheat the entire casting slowly and gradually and uniformly in the 500- to 1 1,200-degree F selection. Be careful to heat within the expressed range as overheating may cause iron to crack. The casting should get hot just to the extent you can to touch it comfortably together with your bare hand. If you need to, make short welds intermittently in order to avoid overheating.
Occurrences of smaller cracks when welding cast ironing, is inevitable. It is possible to apply some sealing compound to prevent leakages. If you can find major cracks you must repair with studding. Studding is a complex process calling for many skills. The first step is to drill and tap holes on the surface that has beveled. The next thing is to put in steel studs and the studs should turn out 5 to 6 mm above the surface and the studs should in that case be welded to remain in place.
Preheated welding could be easily done – particularly for small and manageable things. While welding the cast iron without preheating, it is extremely essential the operator has very good control over the welding gun and generate the welds as small as possible.
Welding cast iron having an arc welder demands different procedure. As a matter of known fact, persons capable of welding cast iron with arc welder are few in number and there’s a great demand for such qualified persons.
You may have to either purchase or hire a SMAW (shielded metal arc welding or stick electrode) welder depending how often you perform cast ironing welding with arc welder. Plug your welder into a 220V outlet and then plug in your ground cord and welder electrode holder cord in to the welder. Please understand that to weld cast iron, you need a special electrode. You may purchase a 770 stay electrode to weld cast iron.
First of all, clean the surface area to end up being welded with a cable brush. Clamp the grounding clamp cord from the welder onto the piece of cast iron that has to be welded. Thereafter, position an electrode in to the welder electrode holder and placement the electrode near where in fact the weld has to begin.
Continue steadily to tap the electrode on the cast ironing till an arc is established and commence to weave the electrode stick laterally. Make it a point to keep the arc slightly away from the piece of steel you are welding. Wait for a few minutes for the weld to cool-down gradually. Utilize the welding hammer to chip off the slag from the very best of the weld.