Hall Petch Validation
MAY 2016
It is commonly known that grain size directly relates to tensile strength. It is an inversely proportional relationship as a smaller grain size will yield a higher tensile strength and vice versa. These two properties can be related with a relationship known as the Hall-Petch equation. This report will focus on verifying the Hall-Petch relationship for a variety of metallic specimens by using experimental results of yield strength and grain size to calculate the constants within the equation.
Advanced Failure Analysis
Failure Analysis Investigation of a Ruptured Natural Gas Pipeline
MAY 2016
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Microstructure of fusion zone revealed distinctive ferrite banding. No banding is present in the base metal.
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TEM analysis reveals presence of broken pearlite and extremely large carbides, and M/A islands
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M/A islands might act as crack initiation site
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Crack propagation might have occurred through ferrite bands
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Fracture mechanism is dominated by transgranular cleavage Evidence of microvoid coalescence SEM analysis revealed evidence of inadequate fusion