Welding in protective gases is the common name of the varieties of arc welding, in which through the burner nozzle into the combustion zone of the arc jet is supplied shielding gas.
Carbon dioxide, argon, helium, nitrogen, as well as mixtures of these gases in different proportions are standardly used as shielding gases today. Two trends are characteristic of modern gas production and use practices. On the one hand – the desire to improve the purity of the gas, and on the other – an increasing variety of gas mixtures that differ in quantitative and qualitative compositions. This is due to an increase in the number of consumers of mixtures, as well as the introduction of new chemical, food, medical and engineering technologies.
Comparing two methods of protecting the weld pool (carbon dioxide and multicomponent gas mixtures), we can conclude in favor of the use of gas mixtures, since only in this method of protection was made possible:
• increasing the amount of deposited metal per unit time;
• reduction of losses of electrode metal for spattering;
• reducing the amount of adhesion of the spray (of spraying) in the area of the weld and, as a consequence, the reduction of labor to remove them;
• increase the plasticity of the deposited metal, especially impact strength;
• stabilization of the welding process and improvement of the quality of the weld metal, namely reduction of u1087 porosity and non-metallic inclusions, provided that the welding wire is uniformly fed into the welding zone.
Considering the economic side of the question, it is necessary to consider a number of additional benefits of gas mixtures:
• increased welding speed and deposition rate, in comparison with welding in CO2 (according to some estimates up to 50%) significantly reduces the effort required per unit length of the weld, reduces the wear of the equipment;
• the operation of cleaning the seam is practically eliminated, since spatter of the electrode metal and spatter on the base metal is minimal (70-80% less);
• reduced costs for welding consumables. (It should also be noted that the metal consumption of domestic welded metal structures in many cases is higher than that of their foreign counterparts, which is largely due to the absence of welding mixtures in the technological process);
• reduced the cost of rework.
Moreover, the transition using pure gases for welding on mixtures does not require significant costs, because most modern devices have several operating modes that allow you to use both pure gas and mixtures. It has also become possible to use domestic welding semiautomatic devices (automatic machines, robots) for welding metal structures using gas welding mixtures.
The use of gas mixtures also affects the reduction of welding production factors harmful to human health. So, the main component of welding mixtures is chemically neutral argon, which is harmful to the human body, according to the official conclusion of the Scientific Research Institute of Occupational Hygiene. What can not be said about carbon dioxide, which, decaying during welding, forms carbon monoxide in the working area.
Thus, the introduction of multicomponent welding mixtures in the welding production is one of the promising directions to increase the reliability, quality and competitiveness of products, reduce its cost, and ensure compliance with international standards.
Remtehgaz company offers the following services in the field of use of welding mixtures:
