Saturday, 7 January 2012

Story Telling: The Princess and the Heat treated plain carbon steels.

I have to write a formal lab report and the brief includes 'story telling'. Here we go.

Once upon a time there was a magical prince who was trapped in a scary castle which had three plain carbon steel doors.
The first door had been heated to 860ºC then allowed to cool.
The second door had also been heated to 860ºC then quenched by dropping the hot metal into water.
The Third door had been heated and quenched like the second one, then heated to 650ºC again.

The princess, who wanted to rescue him, only had one good lance that would break if it was used on a door that was too hard. So the princess, knowing that only one lance meant only one chance, went to the lab to find out which door she should try and break down.

Initially the princess used the Jominy test to determine the Vickers Hardness. The test involved making an imprint with a diamond at set distances from the quenched end then comparing the results for the different samples. From this the princess found that second and third doors had a much higher Vickers hardness.

Next the princess carried out the Charpy impact test, where the samples were hit with a big heavy pendulum and the energy absorbed was measured and from this the princess found the third door was ductile, the second door was brittle and the first door had some plastic deformation.

The princess deduced that although the second door had a harder surface than the first, it would break under smaller force.
So the princess went back to the castle, broke down the second door with her lance then saved the prince. And they lived happily ever after.

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