Flux cored arc welding ppt
-
Upload
gautam-buddha-university-school-of-management -
Category
Engineering
-
view
1.253 -
download
45
Transcript of Flux cored arc welding ppt
NAME MOHD ASLAM 11/IME/065
High-quality weld deposit with excellent appearance
Can be used to join many types of metals over a wide thickness range
Relatively high electrode efficiency and process duty cycle
Excellent weld penetration simplifies joint design
The arc is visible and easy to use
Because of its greater tolerance for base plate contamination, Flux Cored Welding requires less pre-cleaning than MIG
Deposition rate is up to four times greater than Stick Welding
The use of self-shielded electrodes eliminates the need for flux handling or gas apparatus, and is more tolerant of windy conditions present in outdoor construction than gas-shielded processes
Flux cored electrodes may be used for welding carbon steels
low alloy high strength steels
high strength quenched and tempered steels
welding stainless steels and abrasion resistant steels
self-shielded - core provides ingredients for shielding
gas-shielded - uses external shielding gases
In the case of dual shielding being used with a flux cored electrode the choices of shielding gasses are limited. The choices are as follows:
CO2 – Carbon dioxide
Ar – Argon
CO2 / Ar – A mixture of the two
Ar / Ox – A mixture of the two
Flux cored electrodes are tubular
Hollow tube with flux in the center
Flux cored electrodes come in standard sizes
As
.035
.045
.052
1/16
Wire feed speed (and current)
Arc voltage
Electrode extension
Travel speed and angle
Electrode angles
Electrode wire type
Shielding gas composition (if required)
Reverse polarity (Electrode Positive) is used for FCAW Gas-Shielded wire, Straight polarity
(Electrode Negative) is used for self shielded FCAW
Mild and low alloy steels
Stainless steels
Some high nickel alloys
Some wearfacing/surfacing alloys
Porosity chances very low
FCAW may be an "all-position" process with the right filler metals (the consumable electrode)No shielding gas needed with some wires making it suitable for outdoor welding and/or windy conditionsA high-deposition rate process (speed at which the filler metal is applied) in the 1G/1F/2FSome "high-speed" (e.g., automotive) applicationsAs compared to SMAW and GTAW, there is less skill required for operators.Less precleaning of metal requiredMetallurgical benefits from the flux such as the weld metal being protected initially from external factors until the slag is chipped awayFCAW requires with or wthout shielding gas
Melted Contact Tip – happens when the contact tip actually contacts the base metal, thereby fusing the two and melting the hole on the endIrregular wire feed – typically a mechanical problemPorosity – the gases (specifically those from the flux-core) don’t escape the welded area before the metal hardens, leaving holes in the welded metalMore costly filler material/wire as compared to GMAWThe equipment is less mobile and more costly as compared to SMAW or GTAW.The amount of smoke generated can far exceed that of SMAW, GMAW, or GTAW.Changing filler metals requires changing an entire spool. This can be slow and difficult as compared to changing filler metal for SMAW or GTAW.Creates more fumes than stick weldingThin plate does not weld by FCAWA slight change in a knob position can make a big difference in the arc
High production rateflux core welding can weld 1/2" plates in a single pass with full penetration on both sidesFlux core welding produces high quality welds, fast and even when in windy conditions.Used in the ship building industry. Ships are made of heavy
plate
E71T-1 (FCAW-G): Highest deposition rates out-of-position.E71T-8 (FCAW-S): Highest deposition rates out-of-position without a shielding gas.E70T-4 (FCAW-S): Highest deposition rates in the flat position.E70T-1 (FCAW-G): Highest deposition rates in the flat position with Charpy properties.E71T-14 (FCAW-S): Fastest travel speed on galvanized and coated steels.E70T-5 (FCAW-G): Fastest way to weld hard-to-weld steels.
Control the heat to weld thin plate
Control the fumes generate in FCAW
Control noise and spatred at time of welding of material
American Society of Safety Engineers, Are Welding Fumes an Occupational Health Risk Facto
Flux Cored Welding." Welding Procedures & Techniques. 23 June 2006. American Metallurgical Consultants. 13 Sep 2006 <http://www.weldingengineer.com/1flux.htm>.
Groover, Mikell P. Fundamentals of Modern Manufacturing. Second. New York City: John Wiley & Sons, INC, 2002.
"Solid Wire Versus Flux-Cored Wire - When to Use Them and Why." Miller Electric Mfg. Co. 13 Sep 2006 http://www.millerwelds.com/education/articles/article62.html
Wikipedia