WELDING PROCESSES FOR STAINLESS STEEL
WELDING PROCESSES FOR STAINLESS STEEL The stainless-steel welding process varies depending on the thickness and finish of the material. The oxygen surrounding the molten pool of stainless steel must be kept to an absolute minimum. The weld pool of stainless steel will behave differently than aluminum or carbon steel. There are variety of welding methods for Stainless Steel. Here we are discussing about some of them. Gas Metal Arc Welding (GMAW) Gas metal arc welding is one of the most familiarly known and most popular ways to weld stainless steel. There are many similarities between MIG welding stainless steel and welding carbon steel. No special drive rolls need to be used, and the electrical polarity remains the same. However, shielding gas compositions are typically different. Lower amounts of oxygen are allowable when welding stainless steel, so O2 or CO2 levels should be kept around 2% or lower. It is quite common for tri-blend shielding gases that contain argon, helium, and carbon dioxide or oxygen to be used when MIG welding stainless steel. Furthermore, to prevent cracking, the filler wire and base stainless steel should be a low carbon version or have stabilizers in them such as tantalum or niobium. Using a pulsed welding waveform can also help users MIG weld stainless steel more successfully. Gas tungsten Arc welding (GTAW or TIG) This is the most widely used process due to its versatility and high quality as well as the aesthetic appearance of the finished weld. The ability to weld at low current, and hence low heat input, plus the ability to add filler wire when required, make it ideal for thin materials and root runs in one sided welding of thicker plate and pipe. The process is easily mechanized and the ability to weld with or without the addition of filler wire (autogenous welding) make it the process for orbital welding of pipe. Pure argon is the most popular shielding gas, but argon rich mixtures with the addition of hydrogen, helium or nitrogen are also employed for specific purposes. Inert backing gas protection of the weld under-bead is employed with single-sided welding to prevent oxidation and the loss of corrosion resistance. Plasma Arc Welding (PAW) A derivative of the TIG process involving a constructed nozzle system to produce a narrow concentrated transferred plasma arc with deep penetration characteristics. Mainly used in a mechanized system where high speed, high productivity autogenous welding of square-edged butt joints up to 8mm thick is required. With thicker square edged butt joints, a combination of PAW/TIG and filler wire becomes necessary to ensure a full profile weld surface. Thickness greater than 10mm employ a partial v-preparation PAW root weld followed by multi-pass joint filling. Argon backing gas protection is necessary to maintain the corrosion resistance of the under-bead. Metal-Cored Arc Welding A better cored wire alternative to both self-shielded flux-cored arc welding and gas-shielded flux-cored arc welding is metal-cored arc welding. This is most commonly used because metal-cored arc welding does not rely on flux at all. The metal core of the filler material, while it does have certain kinds of deoxidizers, is mostly packed with powdered metals to increase deposition. With the proper shielding gas and wire feeding system metal-cored arc welding can be used to make high-quality welds on stainless steel. For the most part, a pulsed waveform or spray-transfer arc is required to make a high-quality stainless-steel welded tubes and pipes with metal-cored arc welding. Laser Beam Welding (LBW) Laser beam welding is frequently used to join together stainless steel at very fast travel speeds and with very low heat inputs. Cracks and porosity can be avoided through reducing the amount of oxygen via a shielding gas and weld parameter optimization. Care must be taken to avoid porosity and cracking when welding with lasers. Laser beam welding is never performed manually, and therefore, must be automated if it is selected as the process to be used for welding stainless steel. There are most trusted suppliers of Stainless-Steel welded tubes & Pipes in standard number of size and grades in India and abroad. Visit http://santoshsteels.com/ for stainless steel pipe manufacturers in india, manufacturers of stainless steel pipes in india, industrial pipe manufacturers in india, stainless steel tubes manufacturer in india, s s pipe manufacturer in india, stainless steel pipe Suppliers in india, Suppliers of stainless steel pipes in india, industrial pipe Supplier in india, s.s pipe exporter in india, stainless steel pipes and tubes manufacturers in india, stainless steel pipes and tubes Supplier in india, stainless steel pipes and tubes exporter in india.
123 views • 2 slides
