hardfacing

Question 1

What is critical during thermal spray surfacing?

Answer 1

Maintaining correct distance and heat input

Question 2

Which filler metal resists saltwater best?

Answer 2

Copper alloys

Question 3

What is underbead cracking?

Answer 3

Cracking under the weld due to uneven expansion/contraction

Question 4

Define erosion.

Answer 4

Grooving wear caused by moving particles or fluids

Question 5

Define abrasion.

Answer 5

Wear from rubbing or scraping against hard materials

Question 6

Define distortion.

Answer 6

Change in shape caused by uneven heating and cooling

Question 7

How can stress failures be avoided?

Answer 7

Preheat, control cooling, and avoid welding interruptions

Question 8

What does the waffle pattern work well for?

Answer 8

Earthmoving equipment or surfaces exposed to dirt/sand

Question 9

What pattern is used for larger rock or ore impact?

Answer 9

Dot pattern

Question 10

What is the hardest and most wear-resistant hardfacing metal?

Answer 10

Tungsten carbide

Question 11

What is thermal shock?

Answer 11

Cracking from rapid temperature changes

Question 12

What is ABR?

Answer 12

Abrasive wear resistance

Question 13

What causes abrasions?

Answer 13

Sliding or scraping contact removing metal

Question 14

How can excessive dilution be avoided?

Answer 14

Low current, correct polarity, slower travel, more overlap

Question 15

What are ways to reduce surfacing distortion?

Answer 15

Preheat, weld evenly, and use controlled cooling

Question 16

What does MCAW surfacing offer?

Answer 16

Low dilution and high deposition rate

Question 17

What does each part of RWC 2–20/30 mean?

Answer 17

R = rod, WC = tungsten carbide, 2 = composition, 20/30 = mesh size

Question 18

SMAW surfacing is popular because it’s low-cost and simple. True or False?

Answer 18

True