Audio Transcript Auto-generated
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now I'd like to discuss the processing results.
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We did tensile testing on all samples to compare the
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relevant properties.
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The ultimate tensile strength and elongation must be similar after
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treatment. In order for the metal to still work for
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production before treatment, the steel has prominent discontinuous yielding.
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To combat this, we tried a 2% cultural, a 3%
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cultural and then the heat treatment for one hour at
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400 degrees Celsius, followed by a 2% cultural.
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The stress strain diagrams after treatment look quite different.
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So what did we see?
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Change. The highest U.
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T s was seen in sample A.
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Although samples A and B were very similar.
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There's no yield point in sample A and Sample B
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has some evidence of an upper yield point, but no
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further discontinuous yielding.
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After this point, Sample C has prominent discontinuous yielding, although
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not quite as bad as the original sample.
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Cold rolling caused an increase in ultimate tensile strength, but
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a decrease in elongation the heat treatment resulted in the
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opposite the changes.
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Overall, though we're not too severe.
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The property changes that have been discussing here are caused
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by structural changes, cold rolling causes atomic changes such as
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the dislocations to pile up at the grain boundaries.
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It also causes the grains to become elongated in the
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direction of rolling.
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This causes an increase in strength and U.
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T s but a decrease in duct illit e.
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We see this in samples A and B.
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He treatment leads to the relief of stresses within grains,
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but also the segregation of interstitial atoms such as carbon.
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This contributes to discontinuous yield ing's, such as what's seen
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in sample see?