1. High silicon melting flux

According to the content of MnO, high silicon flux can be divided into four types: high manganese high silicon flux, medium manganese high silicon flux, low manganese high silicon flux and no manganese high silicon flux. Due to the high content of Si0 2 (>30%), the silicon can be transferred to the weld through the flux, and the flux with high content of MnO has the function of transition manganese to the weld metal. When the content of SiO2 and MnO in flux increases, the transition amount of silicon and manganese increases. The transition of silicon depends on the amount of silicon in the welding wire. When flux contains MnO<10%(42~48% SiO2), manganese will burn out. When MnO increased from l0% to 25~35%, the transition amount of mn increased significantly. However, after MnO>(25 ~ 30)%, the increase of MnO had little effect on mn transition. The transition amount of manganese is not only related to the content of Si02 in flux, but also related to the content of manganese in welding wire. The lower the content of manganese in welding wire, the better the effect of transition manganese through flux. Therefore, depending on the amount of MnO contained in high silicon flux, different welding wires containing manganese should be selected.

2. Medium silicon melting flux

Due to the low amount of acidic oxide Si02 in this flux and the high amount of alkaline oxide CaO or MgO, the alkalinity is higher. Most of the silicon flux is weak oxidizing flux, weld metal oxygen content is low, therefore high toughness. This type of flux can be used with suitable wire to weld alloy structural steel. In order to reduce the hydrogen content of weld metal and improve the cold cracking resistance of weld metal, a certain amount of FeO can be added to such flux. This flux is a new type of flux for welding high strength steel.

3. Low-silicon melting flux

CaO, Al2O3, MgO, CaF2, etc. This flux has basically no oxidation effect on weld metal, and can be used to weld high alloy steel, such as stainless steel, hot steel, etc.

4. Fluorine-alkali sintered flux

This is an alkaline flux. Can be ac, dc dual-use, dc welding wire connection positive electrode. Maximum welding current up to 1200A. The weld metal has high impact toughness at low temperature. With suitable welding wire, can be used for welding a variety of low alloy structural steel for important welding products, such as boilers, pressure vessels, pipelines, etc. It can be used for multi-wire submerged arc welding, especially for double-sided single-pass welding of large diameter vessel.

5. Si-ca sintered flux

This is a neutral flux. Can be ac, dc dual-use, dc welding wire connection positive electrode. Maximum welding current up to 1200A. Suitable welding wire can be used for welding general structural steel, boiler steel, pipeline steel, etc. Can be used for multi - wire fast welding, especially for double - sided single - pass welding. Because of "short slag", small diameter pipe can be welded.

6. Silicon-manganese sintered flux

This flux is acidic flux, can be ac, dc dual-use, dc welding wire connected to the positive electrode. Suitable welding wire can be used for welding low carbon steel and some low alloy steel.

7. Aluminum-titanium sintered flux (SJ501)

This is a kind of acid flux, can be ac, dc dual-use, dc welding wire to connect the positive electrode. Maximum welding current up to 1200A. Flux has a strong anti - porosity, a small amount of rust film and high temperature oxidation film is not sensitive. Suitable welding wire can be used for welding low carbon steel and some low alloy steel structures, such as boilers, ships, pressure vessels, etc. Can be used for multi - wire fast welding, especially for double - sided single - pass welding.