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Question 1

How high can GTAW welding temperatures reach?

Answer 1

19427^C (35000^F)

Question 2

What’s is shielding gases primary use?

Answer 2

To protect the weld from atmospheric contamination

Question 3

What are the four types of GTAW welds?

Answer 3

Spot welding, hot wire GTAW, cold wire GTAW, high amperage GTAW

Question 4

What is hot wire GTAW?

Answer 4

It’s a mechanized process which feeds wire directly into the puddle, resistance heating preheats the filler metal to a near molten using a separate AC power supply

Question 5

What do hot wire and cold wire GTAW have in common?

Answer 5

They are both mechanized processes

Question 6

What is a common use of high-amperage GTAW process?

Answer 6

It is often used to weld root passes in a carbon steel pipe

Question 7

What gas is used with the GTAW process?

Answer 7

100% Argon

Question 8

At what speed will fans or drafts blow the protective gas envelope away?

Answer 8

50 CFM (cubic feet per minute)

Question 9

What are the 6 key items that the GTAW process requires?

Answer 9

Welding power source, welding torch assembly, work lead, non-consumable tungsten electrode, shielding gas, filler metal (if required)

Question 10

Why must you have post purge settings with GTAW?

Answer 10

It protects the tungsten electrode from deterioration due to oxidation

Question 11

What happens during the peak of a pulsed current?

Answer 11

It’s the period of time when penetration and metal flow occur

Question 12

What is the average range for amount of pulses per minute?

Answer 12

2-10 pulses per minute

Question 13

When using pulsed GTAW on stainless what is the depth to width ration of the weld?

Answer 13

2:1

Question 14

When GTAW welding with out using a filler wire what is this called?

Answer 14

Autogenous welding

Question 15

What are the power source options for GTAW?

Answer 15

Transformers, transformer/rectifier, generators, or inverter type welding machine

Question 16

What metals are commonly welded with AC when GTAW welding?

Answer 16

Magnesium and aluminum

Question 17

Define amperage

Answer 17

Measure if the number of electrons that flow past a given point in one second

Question 18

Define voltage

Answer 18

Pressure needed to push the electrons through the conductor

Question 19

What is the most common gas nozzle? Why?

Answer 19

Ceramic gas nozzles are the most common because they are the least costly

Question 20

How are gas nozzles sized?

Answer 20

They are sized by 1/16”, a number 6 is 6/16”

Question 21

What do gas lenses allow for?

Answer 21

Shielding gas to flow in a laminar fashion (arranged in thin layers)

Question 22

Why is the chemical symbol for tungsten W?

Answer 22

Cause the German term for tungsten is wolfram

Question 23

What direction should grinding marks run on a tungsten electrode?

Answer 23

Longitudinal

Question 24

What kind of tungsten is used with aluminum?

Answer 24

Pure tungsten

Question 25

What are the factors that influence choice of welding filler?

Answer 25

Required mechanical and physical properties, joint design, and required finish or appearance of the welded part

Question 26

Why can't you use a mild steel brush on aluminium?

Answer 26

Because it may deposit carbon into the weld area

Question 27

What affect does the nickel added to stainless steel have on the weld puddle?

Answer 27

It becomes much more fluid

Question 28

What kind of stainless steel is a 300 series?

Answer 28

Austenitic stainless steel

Question 29

Why can titanium be used in tig versus other process?

Answer 29

Because titanium burns up if crossed through an open arc, it's used to stabilize the weld puddle

Question 30

What does appropriate stick out do for the GTAW process?

Answer 30

Maintains gas shield around the electrode and molten weld metal

Question 31

Three ways to strike an arc in GTAW?

Answer 31

Touch start, high frequency start and lift start

Question 32

Name 5 components of a GTAW cable and torch assembly?

Answer 32

Torch handle and head, gas control valves, cable covers, nozzles, collet and collet body, gas lens, and electrode

Question 33

Name two safety devices on a water cooled torch?

Answer 33

A fuse link (if coolant is lost this cause the fuse to melt and stops the system) and coolant flow safety interlock system, this systems tells if there is water flowing through the torch

Question 34

Why would there be a gas control on the torch?

Answer 34

If there are no solenoid valves used

Question 35

When is GTAW preferred?

Answer 35

When the highest possible quality welds for the more critical weld applications

Question 36

At what speed will a draft blow away the protective gas envelope?

Answer 36

50 surface feet per second

Question 37

What does pulse current control?

Answer 37

It controls the high(peak) and low (background) currents

Question 38

What is an advantage of pulsed GTAW?

Answer 38

Greater control of heat input

Question 39

What is orbital GTAW?

Answer 39

It's is a semi and fully automatic welding process in which a welding arc travels 360 degrees around a work price with interruption

Question 40

What metals is DCEN generally used on?

Answer 40

Ferrous metals