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ENGINEERING, PPT 2017 HSC 8 MC

Which row of the table correctly identifies how the properties of a cold worked metal are changed after annealing?
 

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`B`

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  • Generally, annealing is the heat treating of a metal to produce a soft (decrease in hardness), stress reduced (decrease in internal residual stress) state.
  • By decreasing the hardness and internal stress, the ductility will increase as well.

`=>B`


♦ Mean mark 49%.

ENGINEERING, PPT 2019 HSC 24b

Normalised high-tensile steel has been chosen for the manufacture of a wing support beam.

  1. Draw and label the microstructures of a normalised high-tensile steel and an annealed high-tensile steel.   (2 marks)
     

  1. Explain how the microstructure produced by normalising high-tensile steel improves the steel's suitability for this application.   (2 marks)
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i.    Microstructures

 

ii.   The strength of the steel is markedly increased.

  • Normalising produces finer and more uniform grains.
Show Worked Solution

i.    Microstructures


♦♦♦ Mean mark (i) 26%.

ii.   The strength of the steel is markedly increased.

  • Normalising produces finer and more uniform grains.

♦ Mean mark (ii) 41%.