Method for determining magnesium or magnesium alloy corrosion rate and special experimental device

Abstract

The invention discloses a method for determining a magnesium or magnesium alloy corrosion rate and a special experimental device, which have the characteristics of high sensitivity and capabilities of obtaining an average corrosion rate, monitoring an instantaneous corrosion rate simultaneously, converting a hydrogen gas release rate into the instantaneous corrosion rate through collecting and determining the hydrogen gas release rate in a magnesium alloy corrosion process, and obtaining more information about the corrosion process. A hopper is inversely covered on a container with a corrosive medium; a magnesium metal or magnesium alloy specimen is hung inside the hopper; a burette is further inversely covered on the tail end of the hopper; the burette mouth is lower than the liquid level of the corrosive medium; a vacuumization operation is carried out inside the burette, and the solution in the burette is sucked to the highest scale of the burette; the burette is sealed; hydrogen gas, generated through the corrosion of the magnesium metal or magnesium alloy specimen, enters into the space above the liquid level of the burette in a bubble form through the hopper; an amount of the hydrogen gas generated on a unit surface area in unit corrosion time is read through the descending scale change of the liquid level; and the instantaneous corrosion rate or the average corrosion rate of magnesium metal or magnesium alloy on a certain moment is calculated.

Description

technical field [0001] The invention relates to a method and a special experimental device for measuring the corrosion rate of magnesium or magnesium alloys, which can conveniently calculate the corrosion rate of magnesium and magnesium alloys by collecting and measuring the amount and rate of hydrogen released during the corrosion process, and is suitable for magnesium and magnesium alloys. Corrosion Behavior of Magnesium Alloys. Background technique [0002] Magnesium is one of the lightest metals, its density is only 1.7g / cm 3 . Magnesium alloys have high specific stiffness and specific strength, so under the current international background of energy saving and consumption reduction, they are more and more used in automobile transportation, electronics, and aerospace industries. In addition, magnesium reserves are very abundant on the earth, the content in the earth's crust can account for about 2.7%, and the content in seawater is about 0.13%. China is one of the cou...

AI Technical Summary

Problems solved by technology

[0007] (1) The weight loss method can only measure the average corrosion rate during the entire immersion time, but cannot monitor the instantaneous and real-time corrosion rate during the immersion process, which is not easy to understand the corrosion process of magnesium alloys

For example, if one wants to understand the change of the corrosion rate of a magnesium alloy with the soaking time, multiple samples can only be soaked for different times. Influenced by individual differences, the reliability of experimental results will be affected

[0008] (2) Due to the limitation of the weight change caused by corrosion, the sensitivity is low when measuring a small amount of corrosion

[0009] (3) Since the corrosion products need to be removed by the weight loss method, part of the uncorroded magnesium metal will inevitably be removed in the process of removing the corrosion products, thus affecting the reliability of the calculation of the corrosion rate

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