AIT Material Science 3

Question 1

Which stainless steel series is most commonly used in trade applications due to its good corrosion resistance and weldability?

Accepted Answer

300 series (austenitic)

Answer

The 300 series austenitic stainless steels, such as 304 and 316, are most widely used because of their excellent corrosion resistance and weldability.

Question 2

What does the Rockwell hardness test measure?

Accepted Answer

The depth of indentation made by a standard indenter under a fixed load

Answer

The Rockwell hardness test measures material hardness by the depth of penetration of an indenter under a specific load.

Question 3

Which alloying element is added to steel to improve its hardenability and wear resistance in tool steels?

Accepted Answer

Chromium

Answer

Chromium improves hardenability, wear resistance, and corrosion resistance in steel alloys.

Question 4

What is the primary advantage of using aluminum alloys over pure aluminum in structural applications?

Accepted Answer

Significantly improved strength

Answer

Alloying aluminum with elements like copper, magnesium, or silicon greatly increases its strength while maintaining its light weight.

Question 5

In welding and metal fabrication, what is 'scale' that forms on heated steel?

Accepted Answer

Iron oxide formed during heating

Answer

Scale is iron oxide (FeO, Fe2O3, Fe3O4) that forms on the surface of steel when it is heated in the presence of oxygen.

(AIT) Apprenticeship and Industry Training Practice Test

(AIT) Apprenticeship and Industry Training Practice Test

AIT Material Science 3