AWS CWI Part A – WIT Chapter 8

1.

As a metal is heated:

2.

The state of matter which exhibits the least amount of energy is:

3.

A problem occurring in weldments caused by the non-uniform heating produced by the welding operation is:

4.

Which of the following is not a method used to eliminate or reduce residual stresses?

5.

The type of alloying in which the alloy atoms are located in the spaces between the atoms of the parent metal is referred to as:

6.

Rapid quenching of steel from the austenitic range results in a hard, brittle structure known as:

7.

Very slow cooling of steel may result in the production of a soft, ductile microstructure which has a lamellar appearance when viewed under high magnification. This structure is referred to as:

8.

When rapid cooling produces a martensitic structure, what sub-critical heat treatment may be applied to improve the ductility of the steel?

9.

It is determined that a welding procedure is creating an excessive heat input. Which of the changes listed below would result in a reduction of the heat input?

10.

The use of preheat will tend to:

11.

Which of the following changes will warrant an addition or increase in the required preheat?

12.

What heat treatment is characterized by holding the part at the austenitizing temperature for some time and then slow cooling in the furnace?

13.

What heat treatment is characterized by holding the part at the austenitizing temperature for some time and then cooling in still air?

14.

Steel heated above the lower transformation temperature (A1) will change the metallurgical structure. This temperature is:

15.

Atoms in the solid (frozen) state:

16.

What is the heat input for a molten weld pool at 5 ipm travel speed, 25 volts, and 100 amperes?
(Refer to page 10-8 for Formula)

17.

One way that atoms are added to a pure metal to form an alloy is:

18.

The process where carbon is added to the surface of a steel to harden it is:

19.

Steel exists in which of the following crystal structures?

20.

Which of the following usually follows quenching?

21.

Which of the following can be accomplished using either thermal or mechanical techniques?

22.

Which of the following results in the softest condition for carbon steel?

23. For steel having a chemical composition of: 0.16% carbon, 0.84% manganese, 0.09% nickel,
0.25% chromium, 0.052% copper, and 0.40% molybdenum, what is its Carbon Equivalent?

24.

Stainless steels are defined as having at least what percent chromium?

25.

Sensitization, or carbide precipitation, of austenitic stainless steels, can be reduced by which of the following methods?

26.

Metals must be molten for diffusion to occur.

27.

Hydrogen can diffuse into a solid metal at room temperature.

28.

Metals can diffuse into each other when both are in solid form.

29.

The process whereby nitrogen diffuses into the surface of carbon steel is:

30.

Welding metallurgy is concerned with the changes in the metals during welding.