SIF TIPS
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Technical advice in the original SifTips style was started in 1932. ‘Sifbronzing’ is an almost universally recognised way of describing the low temperature bronze welding of sheet steel, cast iron and other metals. The reason behind this fact summarises why Sifbronze, the company which first developed and promoted the technique, is generally considered to be a supplier of top-quality welding rods, wires, fluxes and equipment. ‘Will the Welder’ was a Siftips magazine
that was produced in the early 1930's. The aim was to provide users with ideas and tips as to how to get the most out of their welding equipment. In 2007, Weldability-Sif acquired Sifbronze, the welding consumables division of the Suffolk Iron Foundry, known internationally as Sif. Sif is renowned for its UK manufacturing heritage and for its complete range of quality welding consumables for MIG/GMAW, TIG/GTAW, Arc/SMAW, Oxy/Fuel Welding and Brazing, which have been used globally for almost a century.
On the completion of welding, the casting should be brought once again to a uniform temperature between 600ºC and 800ºC and then allowed to cool very slowly.
RepairWelding of Cast iron Cast Iron is notorious for being a difficult material to repair, however with the correct
consumable and working methods, it can be welded very successfully. It can be fusion welded using the oxy-acetylene process and Sif Super Silicon No 9
welding rods. Broken castings should be aligned and tack-welded into position before pre-heating.
All castings must be carefully supported on firebricks with a space of at least three inches beneath and preheated in a muffle to between 600ºC and 800ºC. An oxy-acetylene flame, of ample capacity for the thickness of metal to be welded, is adjusted to a neutral condition. The edges of the fracture or the sides of the vee groove, are melted by flame application; a little Sif Cast Iron Flux sprinkled in the weld area assists in forming a fluid pool of metal. It is recommended that on the completion of welding, the casting should be brought
once again to a uniform temperature between 600ºC and 800ºC and then allowed to cool very slowly inside the muffle. When the oxy-acetylene process is used correctly, it can be relied upon to provide a
soft and easily machinable deposit with full physical properties similar to those of the parent metal. NB. When welding spheroidal graphite cast iron (SG cast iron) Sif Super SG Cast Iron should be used.
Process Tips Clean the metal – The most important
aspect of welding cast iron is to have the surface clean and free of defects prior to welding. Preheat the component part –This should be carried out slowly and uniformly. Cool Slowly – After welding, the casting must be allowed to cool slowly. (Wrap in an insulating blanket or bury it in dry sand) Use a Low Welding Current – Make the welds in small, approximately one-inch long segments. This will prevent the build up of residual stresses. Peening of weld beads is also helpful. ■
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