If melted by welding rod coating, to classify the characteristics of slag, welding can be divided into acidic and alkaline electrode electrode electrode coating of acid the main component of acid oxides such as silica, titanium dioxide, trioxide iron, basic welding rod coating mainly composed of alkaline oxides, such as marble and fluorite. According to the use of electrodes, welding electrodes can be divided into: structural steel welding, heat-resistant steel electrode, stainless steel welding rod, welding electrodes, low temperature steel electrodes, cast iron welding rod, nickel and nickel alloy electrodes, copper and copper alloys, aluminum and aluminum alloys and special purpose welding rod. If the electrode coating in accordance with the main chemical components to classify, welding can be divided into: titanium welding rod, welding rod calcium titanium oxide, ilmenite welding rod, welding rod of iron oxide, cellulose type electrode, low hydrogen type electrode , graphite electrode and the base type electrode Under different circumstances, there are three types of welding classification: use classification by welding, by coating the main chemical composition, by coating the characteristics of molten slag classification
As the high strength brazing material can be used for brazing force component, more and more widely.
1, aluminum Brazing Alloys: Al-Si alloy based mainly, but also by adding copper, zinc, germanium and other elements to meet the technical performance requirements for brazing aluminum and aluminum alloys.
2, silver-based solder: mainly silver zinc alloy of copper and silver as the base, but also adding cadmium, tin, manganese, nickel, lithium and other elements to meet the requirements of different brazing process, is the most widely used kind of hard solder. As the melting temperature is not high, can wet a lot of metal, and has good strength, ductility, thermal conductivity and corrosion resistance, widely used for brazing mild steel, stainless steel, copper and copper alloy, kovar alloy, refractory metals.
3, copper-based solder: copper and zinc are commonly used, copper, germanium, phosphorus and copper brazing, because of its economy is good, in steel, alloy steel, copper and copper alloy brazing gained wide application.
4, Mn-based solder: the nickel-manganese-based, but also adding chromium, cobalt, iron, copper and other elements to meet the needs of different processes. Mn-based solder good ductility of stainless steel, heat-resistant steel with good wetting, solder joints have a high temperature and high temperature strength and moderate oxidation resistance and corrosion resistance of base metals without significant ablation role.
5, nickel-based brazing alloys: nickel-based solder to join within the normal chromium, silicon, boron, iron, phosphorus and carbon and other elements. The main role of chromium is to increase the antioxidant, corrosion resistance and improved high temperature strength of the solder; silicon can reduce the melting point and increase mobility; boron and phosphorus is to reduce the solder melting point of the main elements, and can improve the wetting and spreading capacity; carbon can reduce the solder's melting temperature; a small amount of iron can increase the strength of solder. Nickel-based solder with excellent corrosion resistance and heat resistance, commonly used in brazing austenitic stainless steel, duplex stainless steel, martensitic stainless steel, nickel-based alloys and cobalt-based alloys.
6, gold-based solder: gold-based solder to join within the normal copper, nickel and other elements. Gold-based brazing material and the role of base metal of small, thin pieces commonly used in brazing.
7, palladium-based solder: Palladium-based solder to join within the normal silver, copper, manganese, nickel and other elements. Palladium-based solder with wetting ability, steam down, good ductility, high strength, corrosion tendency of the base metals and other characteristics, suitable for stainless steel, nickel-based brazing alloys and other materials, mainly used in aviation and aerospace, electronics industry and other sectors.
Second, the soft solder
Commonly used tin-based solder, lead-based solder, cadmium-based, zinc-based solder and gold-based materials such as gallium-based low melting point solder, bismuth-based and indium-based solder.
Is the most widely used tin-lead solder. When the tin-lead alloy WSn 61.9%, the melting point of 183 â„ƒ that the formation of the eutectic, the highest strength and hardness.