3 wt% - incorrect, if you look on the diagram you will see that at 3
wt% there is still quite a significant amount of corrosion that can occur.
Try again.
6 wt% - incorrect, the amount of corrosion that can occur is
certainly less than if there were no chromium present; however there is
still too much to say that the steel has almost complete corrosion protection.
Try again
9 wt% - incorrect, the amount of corrosion that can occur is certainly
less than if there were no chromium present; however there is still too much to
say that the steel has almost complete corrosion protection. Try again
12 wt% - correct, the level of corrosion has been reduced
significantly by the addition of 12 wt% Cr, and any additional increase in Cr
level has little effect on corrosion resistance. A steel with greater than
12 wt% Cr in it is called a STAINLESS STEEL.
15 wt%- incorrect, this level of Cr will give almost complete
corrosion protection; however, it is not the minimum required. Try again.
Try again.
Click on your answer to check and make a note of the answer on your notepad.
What is the minimum
level of chromium required to give the steel almost complete corrosion resistance? 
3 wt% - incorrect, if you look on the diagram you will see that at 3
wt% there is still quite a significant amount of corrosion that can occur.
Try again.
12 wt% - correct, the level of corrosion has been reduced
significantly by the addition of 12 wt% Cr, and any additional increase in Cr
level has little effect on corrosion resistance. A steel with greater than
12 wt% Cr in it is called a STAINLESS STEEL.
