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Residual Stresses Reduction for 2024 Aluminum Drill Rod in Geologic Drilling Applying Cryogenic Treatment

Abstract:

The influence of cryogenic treatment on alloy 2024 has been investigated in order to reduce residual stresses, and include this treatment in the manufacturing stages of drill rods for Fruta del norte (FDN) project. In order to increase the efficiency in geological drilling for FDN project, this work proposes the use of aluminum rod drills to reduce the size and energy required of drilling equipment, considering the difficult-to-access deposit location. According to the treatment, after quenching, the samples were cooled down in liquid nitrogen at -196 °C for 5 minutes, following by a rapid heating in hot oil at 180 °C and finally the samples were artificially and natural aged. Another group of samples was treated without cryogenic treatment to compare with the first group of samples. Residual stress was measured by the hole drilling method. The results revealed that this treatment is able to relieve up to 70% of residual stresses in the treated samples.