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Discontinuity Characterization in Standard Nodular Iron using Nondestructive Techniques

Nodular irons have been used with increasing frequency because of their relevant mechanical properties compared to its cost. However, they have defects sometimes associated with solidification, which decreases their mechanical properties. This study analyzed the types of defects in a new nodular iron alloy 100-70-03, which are typically used in the automotive industry. The techniques used in the analysis were microstructural characterization and nondestructive tests such as ultrasound, penetrating liquids, and hardness tests. The results of the microstructural characterization identified nodular iron with a pearlitic matrix. The nondestructive testing revealed defects consisting of voids, microshrinkage, porosity, and microporosity. The dye tests showed porosity on the surfaces, while hardness testing revealed that the material is within the specification. At the end of the characterization, it was found that the new alloy has the proper microstructure and hardness.

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