As mentioned above highlight a number of flux-cored welding favorable characteristics, such as playing with some flux coated electrode can improve the filler metal chemical composition and mechanical properties of the function. Have on production efficiency gas metal arc welding and submerged arc welding characteristics.
Flux-cored wire for carbon steel, low alloy high tensile steel, high strength quenched and tempered steel, stainless steel and wear-resistant steel and other hard surface welding.
FCW is a promising new type of welding material, made in recent years, increasing the amount of variety and Flux Cored Welding Wire. Compared with the solid flux-cored wire has the following advantages and disadvantages.
(1) Advantages:
1) The welding of various steel products, adaptable to adjust the composition and flux ratio is very convenient and easy, can provide the required chemical composition of the weld.
2) process performance, using gas forming beautiful candle residue seam joint protection, get a good shape. Stabilizing agent added to the arc-arc stability, metal transfer evenly.
3) The deposition speed, high efficiency under the same flux-cored welding current the current density, melting fast, the deposition rate of about 85% -90% higher productivity than the welding arc about 3-5 times.
4) The welding current can be larger all-position welding.
(2) shortcomings
1) wire manufacturing process is complex
2) When welding, wire feed problems than solid wire
3) the appearance of easily corroded wire, powder easily to absorb moisture, so keep a flux cored wire management requirements more stringent
3.1, the function played by flux components:
With the same electrode coating, flux cored wire manufacturers of the ingredients are its unique formula, with different functions applicable welding, flux components, which are also different.
The basic function of flux components outlined below:
(1) In addition to nitrogen and oxygen scavenger agent
As the nitrogen and oxygen can cause holes or weld metal embrittlement, flux must be added to manganese and silicon, oxygen scavenger, as self-shielded flux cored wire, flux in the AL to the other need to add nitrogen removal agent. Adding more oxygen than nitrogen agents and cleaning agents aimed at the filler metal.
(2) welding slag-forming agent
Calcium, potassium, sodium or silicon are welding slag-forming agent, added to the flux can effectively protect the weld pool from atmospheric contamination, welding slag, welding props can make a better appearance and rapid cooling after welding can support full-time position the pool. Slag welding filler metal covering more ease the cooling rate, this feature is particularly important for low alloy steel welding.
(3) arc stabilizer
Sodium and potassium can also lower the arc to maintain smooth soft splash.
(4) alloying elements
Molybdenum, chromium, carbon, manganese, nickel and vanadium alloying elements such as add, can increase (improvement) filler metal strength, ductility, hardness and toughness.
(5) gas-forming agent
Fluorspar, limestone, etc. need to add in the Types Of Welding Wires manipulation to protect the combustion gases.
3.2 the type of welding slag
Flux components of the decision of welding consumables and welding filler metal operating mechanical, flux components in terms of acid-based, acid generated after welding welding slag, similar to alkaline (calcareous) will produce alkaline-based solder flux slag. Welding consumables acid system is very good, smooth and stable arc welding process, arc shape similar to the jet, flying less, welding personnel operating on the wide favorite, filler metal mechanical common but up to AWS specifications.
The welding flux as the basic system filler metal can get very good ductility and toughness, but the operation of the system worse than acidic. Droplet transition than the transition to the main ball drop, splash more.
In recent years, low alloy steel welding flux system development combines the operations of the Department of acidic and alkaline series of fine mechanical
(1) according to the different manufacturing methods, flux-cored wire can be divided into: a seam seamless flux cored wire and flux-cored two. Seamed flux-cored wire is a thin strip through the roll forming process into a groove, which roll into powder, then rolled into a tubular wire drawing, processing and manufacturing made of low carbon steel commonly used raw materials, finished surface rust wire surface treatment to the same time to have good wire feeding performance, so the surface. no slit flux-cored wire is pre-filled steel pipe forming a good powder, and then after plating, wire drawing, wire products to the diameter size.
(2) according to the different shielding gas welding, flux-cored wire can be divided into: gas shielded flux cored wire and self-protection in China, Japan, South Korea, flux-cored CO2 as a shielding gas is mostly , while the self-shielded flux cored wire used in the United States the ratio is relatively high, gas prices in Europe because of the protection the difference, flux-cored wire mainly mixed gas (Ar-CO2) protection.
(3) according to different purposes, can be divided into flux-cored wire: low carbon steel and 490MPa grade steel, high strength steel, heat-resistant steel, cold steel, is corrosion of steel, stainless steel, and hardfacing flux-cored wire surfacing due to flux-cored wire can adjust the internal medicine core formula, so with the same hand-welding, flux-cored wire of the variety, there is the location for the entire shipbuilding industry type flux cored wire, a low-temperature flux-cored wire for marine structures, there is used for boilers, heat-resistant pressure vessel steel flux cored wire, and so on.
(4) according to the different composition of the powder filling, can be divided into the slag-type flux-cored type flux cored wire metal powder flux cored wire. Slag-type flux cored wire according to the alkalinity can be divided into titanium slag type (acidic residue) , titanium calcium type (neutral or alkaline residue) and basic (alkaline residue) flux cored wire. In general, titanium cored wire weld is good, all-position welding operability is good, but the notch toughness , somewhat less crack resistance on the contrary Welding Wire China notch toughness. good crack resistance, and weld appearance. forming and operational backward. titania type flux cored wire in between in recent years With the development of flux-cored wire, the new titanium-based flux-cored welding process is not only good, and its proliferation of deposited metal with low hydrogen content, excellent toughness, while the lime-titania type flux cored wire is now rarely used. metal powder flux cored wire with a solid wire-type low-slag (slag produced small amounts), good crack resistance characteristics, and the mix of titanium cored wire welding operations good performance of its welding efficiency than the titanium-based medicine wires for even higher.
Currently no agreed classification of flux-cored wire standard, many countries according to the type and flux-cored form of droplet transition flux-cored roughly classified into four types, namely, titanium, alkali type of metal powder-based and self-protection type flux cored wire.