Flashcards in Welding Processes Deck (19)
Name principle groups of processes included in fusion welding
oxy-fuel welding welding
other fusion-welding processes
What is the fundamental feature that distinguishes fusion welding from solid-state welding
fUSION WELDING IS JUST THE USE OF HEAT FOR WELDING
SOLID STATE WELDING USES PRESSURE OR PRESSURE WITH HEAT
define what electrical arc welding is
Fusion-welding process in which coalescence of the metals is achieved by the heat of an electrical arc between an electrode and the work
what do the terms arcon time / arc time mean
the proportion of hours worked that arc welding has accomplished
Electrodes in arc welding are defined into two types. Define those two types
consumable - provide the source of filler metal in arc welding and is depleted over time
non-consumable - made of tungsten and is gradually depleted.
What are two basic methods of arc shiedling
Covering the electrode tio
molten weld pool with a blanket of gas or flux
combination of the above stated
Why is heat transfer factor in arc welding processes that utilize consumable electrodes?
Molten metal from the electrode is transferred across the arc and contributes to the heating of the molten metal
Describe the shielded metal arc-welding process
Uses a consumable electrode consisting of a filler metal rod coated with chemicals that provide flux and shielding.
why is shielded metal arc welding process difficult to automate
Electrodes must be changed frequently.
describe submerged arc welding
Uses a continuous, consumable bare wire electrode and arc shielding is provided by a cover of granular flux..
Why are temperatures much higher in plasma arc welding than in other processes?
Arc is restricted in diameter, thus concentrating the energy into smaller area
Define resistance welding
.Utilizes a combination of heat and pressure to accomplish coalescence of the two faying surfaces
Describe the sequence of steps in the cycle of a resistance spot welding
1) Insert parts between electrodes
2) Squeeze parts between the electrodes
5) Open and remove
What is resistance projection welding
Coalescence occurs at one or more relatively small contact points on the parts
Why is the oxyacetylene weldingprocess favored over the other oxyfuel welding processes
Acetylene and oxygen burn hotter than other oxy-fuels.
Electron beam welding has a significant disadvantage in high-production applications. What are those disadvantages?
.Must be performed in a vacuum
Laser-beam welding and electron-beam welding are often compared because both produce very high power densities. LBW have certain advantages over EBW. What are they?
No vacuum chamber
Lasers can be focused/directed easily
What is friction stir welding and how is it different from friction welding?
Solid state welding process in which a rotating tool is fed along the joint line, generating friction heat and mechanically stirring the metal to form a weld seam