Welding Knowledge 2: Welding Materials - xlweld.com
Welding Knowledge 2: Welding Materials
Second, welding materials
1. What is welding material? What's included?
A: Welding materials include electrodes, welding wire, flux, gas, electrodes, gaskets and so on.
2. What is welding wire?
A: welding as a filler metal, while the wire used for conductive - called wire. Split solid wire and flux cored wire two. Common solid wire type: ER50-6 (grade: H08Mn2SiA).
3. Why does the MAG welded joint have higher impact toughness than the CO2 welded joint?
A: MAG welding, the active gas is only 20%, the welding element in the alloy transition coefficient is high, the impact of high toughness of the weld. CO2 welding active gas is 100%, the wire in the manganese, silicon alloy element combined deoxidation, the alloy element transition coefficient is slightly lower, the impact toughness of the weld as MAG welding high. Such as Tangshan Kobelco MG-51T welding wire (equivalent to ER50-6) its normal temperature impact toughness value: MAG: 160J; CO2: 110J.
4. What is flux cored wire?
A: rolled from a thin steel strip into a circular steel pipe, at the same time in which a certain composition of the powder, the drawn from a wire.
5. Why is flux cored wire protected with CO2 gas?
A: According to the protection of different ways to distinguish between the flux-cored wire: the core of the gas-shielded wire and the core of self-welding wire. The core of the core gas welding wire is generally used for the protection of CO2 gas, is a combination of air dregs protection form, good weld forming, comprehensive mechanical properties.
6. Why does the flux cored wire weld the indentation pores?
A: Because the flux cored wire is made of thin steel strip rolled wire, belonging to the seam welding wire; air in the water through the gap into the core, the glue wet (can not be dried), resulting in weld indentation stomata.
7. Why is there a technical requirement for CO2 gas purity?
A: The general CO2 gas is a by-product of chemical production, purity is only about 99.6%, containing trace impurities and moisture, will bring holes and other defects in the weld. Welding important products must use CO2 purity ≥ 99.8% of the gas, weld pores less, low hydrogen content, good crack resistance.
8. Why is there a higher technical requirement for argon purity?
(Pure 99.9%), pure argon (purity 99.9%), high purity argon (purity 99.99%), the first two can be welded carbon steel and stainless steel; welding aluminum and Aluminum alloy, titanium and titanium alloy and other non-ferrous metals must use high purity argon; to avoid the weld and heat affected zone is oxidized can not be welded.
9. Why do TIG Welding nozzles have a variety of sizes?
A: There are 4-8 # five kinds of specifications nozzle, welding carbon steel can choose 4-5 # nozzle, welding stainless steel and aluminum and aluminum alloy should use 6-7 # large nozzle to strengthen the weld and heat affected zone protection The Welding titanium and titanium alloy and other non-ferrous metals should be used 7-8 # larger nozzle, in order to prevent the weld and heat affected zone is oxidized.
10. What is an acid electrode?
A: The coating contains a large number of acidic oxide electrode, such as knot 422 (E4303), junction 502 (E5003) and other AC and DC welding electrodes.
11. What is alkaline electrode?
A: The coating contains a large number of alkaline oxides containing fluoride at the same time the electrode, such as junction 507 (E5015), junction 506 (E5016) and other welding electrodes.
12. What is the cellulose type (for the vertical welding) electrode?
A: The skin contains a lot of organic matter in the electrode, pipe and thin structure under the vertical welding. <1> such as E6010 (equivalent to E4310, J425G) for bottoming, heat welding, filling welding.
<2> E8010 (equivalent to E5511, J555) for thermal welding, filling welding, cover welding layer. Generally with low hydrogen welding to the lid; E7048 (equivalent to J506X) weld appearance neat, beautiful.
13. Why should the electrode be dry before welding?
A: The electrode is often due to moisture absorption process performance deterioration, resulting in arc instability, splash increases, and prone to pores, cracks and other defects. Therefore, the electrode must be used before the strict drying. General drying temperature of the electrode electrode 150-200 ℃, time 1 hour; alkaline electrode drying temperature 350 - 400 ℃, time 1 - 2 hours, after drying in the 100-150 ℃ incubator Inside, with the use of take.