Analysis of Solubility Change of Soluble Magnesium Alloy by Melting Treatment in Petroleum Downhole

Abstract

In order to solve the problem that the material utilization rate of soluble magnesium base alloy rod is less than 30%, the method of magnesium alloy rod casting is adopted to improve the material utilization rate. However, the cooling mode affects the dissolution rate of soluble magnesium alloy after casting. According to the different thermal conductivity of different materials, cylindrical graphite molds and copper molds with diameters of 5mm and 40mm are selected for casting magnesium alloys. In order to ensure the reliability of experimental results, polarization method and weight loss method were used to analyze the dissolution rate of soluble magnesium base alloy under different cooling modes. The test results show that: Magnesium alloy is cooled and solidified by copper mold with a diameter of 5mm, and the dissolution rate is the highest in 1.5% NaCl solution with a speed of 1.2856mm/h. The grain size of magnesium alloy can be refined by increasing cooling rate. After the grain boundary of magnesium-based alloy is refined, the grain boundary between the alloy increases, the number of corrosion galvanic cells increases, and the dissolution rate of magnesium-based alloy gradually increases.