We discuss galvanized steel welding procedure and electrode here. One of the metals that most welders have many problems with welding is steel or galvanized sheet. Welding of galvanized sheets requires special skills, and the operating points in the welding operation must be comprehensively and fundamentally observed. It is good to know that welding the galvanized sheet is almost the same as welding uncoated steel of the same composition. In fact, the many advantages that galvanized steel brings to the industry have led to its welding being associated with certain sensitivities. Before we get into the topic of welding galvanized sheet, it is best to understand what galvanized sheet is and what it is used for. If the steel sheet is coated with the metal "zinc", a galvanized sheet is produced. If the coating on these sheets is lost or even broken, this sheet will not rust at all. Sheet galvanizing is done by two methods, the so-called hot-dip galvanizing and cold-dip galvanizing. Hot dip galvanizing is used in more industries and offers more desirable properties. Welding of galvanized parts Although galvanized sheet comes from the steel sheet family; due to the zinc coating, different technical points need to be considered when welding. 
For welding galvanized steel, especially galvanized sheets, a high-speed electrode should be used, which has a thinner surface than other steel parts. Galvanized sheet welding differs from other sheets by the low evaporation temperature of the galvanized layer; because zinc melts at around 420°C and evaporates at around 907°C. Assuming the steel melts at 1538°C and the welding arc temperature is 8000-11000°C, the zinc near the weld will evaporate. Note that the evaporation of zinc occurs with the increase in welding fumes. In addition, the zinc near the welding line is burned by the heat of the arc, and its protective coating is destroyed. Therefore, consideration should be given to welding galvanized sheets by suitable methods. Welding method of the galvanized sheet the welding methods of these sheets are different, and the selection of the correct method should consider the needs and working conditions. Below we will introduce various methods of welding galvanized sheets in the industry. 1. Arc welding under the protection of shielding gas metal arc welding or GMAW is a type of welding that uses a shielding gas and a consumable electrode, also known as CO2 welding; because in this method, carbon dioxide gas is used as the shielding gas. This method is a semi-automatic and versatile process, especially suitable for welding steel sheets and thin sections. The high carbon dioxide content in this weld results in less spatter and better weld quality. In addition, the arc stability of this method is excellent and generally unaffected by the zinc coating. Galvanized steel can use a shielding gas containing CO2 (100% CO2), eliminating the need for more expensive shielding gases. 
2. Arc welding with coated electrodes One of the most common welding methods in the industry is arc welding with coated electrodes, also known as SMAW and electric welding. Electrode movement in this galvanized sheet welding method helps to evaporate the zinc coating and prevent blowholes and cracks. To obtain high-quality and flawless welds in this method, you must choose the most suitable electrode. 3. Oxyacetylene welding an ancient welding method is oxyacetylene (oxygen) welding, which is still widely used in industry due to its unique properties. In fact, any combustible gas combustion that uses oxygen as a heat source for welding is called oxygen welding. In this method of welding galvanized sheets, the flame generated by the combustion of the combustible gas and oxygen generated in the torch head is used to melt the base metal and the welding wire. In this method, combustible gas and oxygen enter the mixing chamber of the burner in the proper ratio, mix and exit the nozzle head of the burner and ignite. One of the most important advantages of oxyacetylene welding compared to other processes is the low maintenance cost of welding equipment. 4. Resistance welding When the connecting steel plate is thinner than 5mm and the coating is lighter than 300g/m2, which is equivalent to a thickness of 43 microns, resistance welding or resistance spot welding can be used. Resistance welding is a cost-effective method of welding galvanized sheets because it causes the least damage to the galvanized sheet. Note that resistance welding is impractical if the galvanized sheet is very thick. 5. Laser beam welding One of the latest welding technologies that have been widely used in many industries including electronics and automotive in recent years is laser beam welding. 
In the laser welding method, heat and laser radiation are used for welding. In fact, laser welding is a process in which, with the help of the heat obtained by the effect of light on the surface, the melting and fusion zones of the material are formed after solidification, thereby forming a connection between the materials. One of the disadvantages of laser welding galvanized sheets is that since the sheets are welded together with no or very small seams, evaporated zinc between the sheets remains in the weld area and creates porous holes.
- What is Galvanized steel Electrode Welding?
Galvanized sheet electrodes as we mentioned, a widely used and ancient method of welding galvanized sheets is to use electrodes, which is usually done manually. In fact, the meaning of electrode is the coated wire that performs the welding operation. This wire is made of aluminum, stainless steel metal, nickel, or a low-carbon compound and is coated with asbestos, lime, sodium oxide, etc. It is generally advisable to be cautious when choosing the electrode type; because electrodes welded with argon must be of medium size. The maximum thickness considered for this type of electrode is about 2.5 mm, and the current is considered between 10 and 200 amps. Medium-sized electrodes produce high-quality welds on galvanized sheets. The most important electrodes for welding galvanized sheets are Electrode 7014 Electrode 7018 Electrode 6011 Electrode 6010 How to Weld Galvanized Sheet Choosing the right current for the electrode you want, between 35 and 40 degrees Celsius, is the first point you should pay attention to when you start welding. 
After choosing the correct current, you need to place the two edges of the workpiece to be joined against each other. Then install the electrode in the correct position and start the welding operation after observing all safety measures. At the end of the operation, the electrode is covered with powder. Galvanized Sheet Welding Problems Welding of galvanized profiles has long been a very big problem for operators. For this reason, most manufacturers prefer to have their product fully prepared and galvanize the entire part at the end; however, in some applications, manufacturers do not have access to such facilities and welding is inevitable. The following are some of the most significant issues: 1. Corrosion When welding galvanized sheets, the galvanized layer in the welding area must be removed first, and then re-galvanized after welding; because the heat generated by welding will destroy the galvanized layer in the welding area. In addition, the mechanical properties of the welded area are generally weaker than the rest of the workpiece due to the sudden heat experienced by the welded area. It should be noted that if there is a gap between the cleaning and welding of the steel coating, the underlying steel may oxidize, rust, or corrode under the influence of the atmosphere or other factors. 2. Presence of zinc coating in galvanized sheets is another challenge we face when welding these sheets. This material can make welding difficult in many ways. For example, the penetration of molten zinc makes welding more difficult and causes voids and pores in the weld. 3. Safety and health of welders Zinc oxide (ZnO) is a zinc coating that melts and even evaporates when in contact with the welding process. The substance is highly toxic and can even be fatal if inhaled in the long term; therefore, there are always some restrictions on the use of welding on galvanized parts. Safety Tips for Welding Galvanized Sheet When welding steel and other metals, safety and health principles must be strictly adhered to. To protect the eyes and face from radiation, special welding masks must be used. In addition, it is important to use special gloves, flame retardant clothing, helmets, welding goggles, be in the welding environment, light, and insulated welding shoes, keep away from flammable materials, etc. 
Arc Welding with Shielded Gas Electrodes (GMAW) in Galvanized Sheet Welding This method, also known as the CO2 welding method, is semi-automatic and multipurpose for welding thin sections and steel sheet products. In this method, the zinc coating does not cause any problems. Of course, its appearance may change due to welding. It is sufficient to use 100% pure CO2 gas for welding galvanized sheets, and there is no need to use expensive gas. It should be noted that the welding penetration of galvanized sheets and coated sheet is smaller than that of uncoated steel sheets. The difference between the two is that the heat in the coated steel must be higher to remove the zinc from the molten pool. Also, the welding speed is low to burn and remove zinc. It should be noted that the evaporation of zinc caused by the high boiling point is very harmful to the health of technicians, so measures should be taken in this regard. For example, it is better to weld galvanized sheets in the open air. Either mechanically or by grinding Joshef's line, he removes that part of the zinc so there are no problems. Bar arc welding (SMAW) This welding is one of the most common types of welding. In this method, coated electrodes are used. While the welding conditions for this method are generally like those of bare steel, it requires its own special skills. For example, they reduced the angle of the electrode to 30 degrees and kept molten zinc away from the welding wire by whipping the electrode back and forth. The main difference between non-stick plate welding and galvanized plate welding is that the penetration of the weld to the base metal must be increased. It should be noted that the amount of slag during welding of galvanized steel is higher than that of uncoated steel. As mentioned earlier, the main difference between galvanized sheet welding and uncoated sheet is that galvanized sheet requires more input heat and lower speed. 
Of course, with this measure, the slag may become more fluid, and the weld slag may increase, which may lead to rust and corrosion in the weld area in the long run. Therefore, technicians should obtain the best-galvanized sheet welding method according to their experience and skills. Other electrodes used in galvanized sheet welding include titanium oxide, cellulose, and low hydrogen electrodes, which we will examine below. Rutile or titanium oxide electrodes in galvanized sheet welding This electrode is usually used for general welding. The presence of large amounts of titanium dioxide in the composition of these electrodes stabilizes the arc. And offers the possibility of welding for all situations.
- Conclusion
All information mentioned above providing to the buyers who want to know and buy metal steel products with professional and innovative thoughts, and passionate and enthusiastic attitudes. Our vision is to be a standard for customized products and quality services so that we can build a good brand image of our company in the national and international market with competitive prices and cheap shipping services. We are eager to do what we do and strive to further the needs of our customers by providing quality products and services. And do not hesitate to any questions our support teams are available. For more information kindly visit our site.