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Stainless ‘An Introduction & guide to ’

Technical advice in the original SifTips style which started in 1932 Sifbronzing is an almost universally recognised way of describing the low What is TIG welding is the most popular process temperature bronze welding of sheet steel, for high quality applications or root runs, cast iron and other . The reason Stainless steel is a generic term for a prior to filling with an alternative process. behind this fact summarises why Sifbronze, range of that contain a minimum TIG Consumables are available in the the company which first developed and of 12% , although other SifSteel Stainless range covering 308L, promoted the technique, is generally considered to be a supplier of top-quality elements such as nickel and 309L, 310, 312, 316LSi, 347 & Duplex. welding rods, wires, fluxes and equipment. are added to improve corrosion resistance, which is their primary feature MIG welding can also be used with increased speed being the main ‘Will The ’ was a Siftips magazine and use. Stainless Steels are grouped that was produced in the early 1930’s. The primarily into four classes depending on advantage. Recent technological advances in welding equipment have enable more aim was to provide users with ideas and tips their crystal structure; austenitic (302, as to how to get the most out of their welding aphetically pleasing results. MIG 304, 308, 316, etc.), martensitic (410, equipment. and 416), ferritic (409, and 430.) and consumables are available in the SifMig duplex (2304, 2205, 2507 etc). The range covering 308LSi, 309LSi, 312, In 2007, Weldability-Sif acquired groups of stainless steel most commonly 316LSi & 347. Plus flux cored wires Sifbronze, the welding consumables division welded are austenitic and duplex. covering 308L, 309L & 316L. of the Suffolk Iron Foundry, known internationally as Sif. Sif is Austenitic Stainless Steels MMA (Manual Arc) can also be used renowned for its manufacturing heritage and successfully in applications or locations for its complete range of quality welding which make it difficult to adopt other consumables for Austenitic steels have austenite as their process. MMA consumables are available MIG/GMAW, TIG/GTAW, primary phase (face centered cubic) in the SifChrome range covering 307, Arc/SMAW, Oxy/Fuel structure. Austenite steels make up over 308L, 312 & 316L. Welding and Brazing, which 70% of total stainless steel production. have been used globally for They contain a maximum of 0.15% TIG or MIG brazing can be used and is almost a century. , a minimum of 16% chromium especially useful if the material is required and sufficient nickel and/or manganese to be joined to or steel. The most to retain an austenitic structure at all suitable consumable in this case would be temperatures from the cryogenic region Process Tips Sifphosphor Bronze No 8 or SIFMIG 8, to the melting point of the . Cleanliness of the workpiece is most important.

Only use stainless wire brushes for cleaning. Duplex Stainless Steels Gas Processes

Avoid striking the arc outside the joint, as this It is possible to gas weld the common Duplex Stainless Steels have a mixed can lead to pitting and cracks. With TIG, use a grades of stainless, but it is important to microstructure of austenite and ferrite thoriated tungsten and do not allow it to contact use Stainless flux and also apply the flux in and have roughly twice the strength the workpiece, which can lead to contamination. paste form (mix powder with water) to the compared to austenitic stainless steels reverse side of the joint. After welding, clean thoroughly using a and also improved resistance to stainless brush. Use SIF Pickling Paste to clean localized corrosion, particularly pitting, Stainless Steel can also be silver soldered discoloration from surface and restore chrome crevice corrosion and stress corrosion or brazed, which is again a benefit for layer on the stainless. cracking. They are characterized by dissimilar metal applications. To silver high chromium (19–32%) and The weld can become contaminated and 'rust' solder stainless, a high silver content alloy molybdenum (up to 5%) and lower spots appear on the stainless if ferrous is required (such as SIF Silver Solder No nickel contents. particles have inadvertently been allowed to 43 55% Ag Cd free) and a suitable flux enter the weld area.

(SIF Flux Silver Solder). Joining Stainless Steel This can be caused by poor housekeeping Alternatively, a 'nickel bronze' brazing rod (stainless brush being used on steel) or other When welding stainless steel it is such as Sifbronze No 2 together with 'Tool operations in the welding area which produce air borne metal particles, such as grinding. imperative that the weld and root face Tipping/Brazing Stainless' flux (note: do

are protected from the atmosphere to NOT use Stainless flux as it is for gas eliminate the creation of chromium welding of stainless) carbides.

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