Novel zinc alloy sacrificial anode in hot seawater environment

Abstract

The invention discloses a novel zinc alloy sacrificial anode in a hot seawater environment. The novel zinc alloy sacrificial anode is characterized by being mainly prepared from Zn-Mg-Si alloy, wherein the zinc alloy sacrificial anode comprises the following components in percentage by weight: 1.5-3.0% of Mg, 0.3-0.6% of Si, the impurity contents are at most 0.05 of Pb at most 0.004% of Cd, at most 0.002% of Cu, at most 0.002% of Fe and the balance of Zn. The novel zinc alloy sacrificial anode has the technical effects that actual measurement proves that the actual electric capacity of the anode is larger than 805A h / kg, the working potential of the anode meets the design requirement on cathode protection, uniform surface solvation is realized, corrosion products are easy to fall off, and the novel zinc alloy sacrificial anode can be used for cathode protection for structures in the hot seawater environment.

Description

technical field [0001] The invention belongs to the field of marine engineering equipment manufacturing, corrosion and protection technology, and specifically relates to a novel zinc alloy sacrificial anode suitable for hot seawater environments. Background technique [0002] In recent years, with the development of offshore oil extraction and oil processing industry, the mileage of oil pipelines has increased rapidly, and the environment they are in is also complicated, such as the seabed and soil. Oil pipelines are inevitably subject to corrosion in these environments. Corrosion damage to oil pipelines will not only cause economic losses, but also cause environmental disasters or endanger public safety due to crude oil leakage. Therefore, anti-corrosion measures must be taken for oil pipelines. [0003] For submarine oil pipelines, the main anti-corrosion measures are combined anti-corrosion coating and sacrificial anode protection. However, the corrosive environment of t...

AI Technical Summary

Problems solved by technology

However, the corrosive environment of this submarine oil pipeline is special: in order to improve the fluidity of crude oil, it is often necessary to heat up, so that the ambient temperature around the pipeline is often between 50 and 70 ° C. Therefore, traditional sacrificial anodes are used here. Under all working conditions, the performance drops sharply

For example, when ordinary ternary zinc (Zn-Al-Cd alloy) anodes are used at high temperatures, intergranular corrosion will occur, the current efficiency will be greatly reduced, the potential will shift positively, and the potential will even become more positive than steel, which will not only fail to protect steel facilities , but accelerates its corrosion

The surface of traditional aluminum alloy sacrificial anodes is easily passivated in high-temperature seawater, forming a hard shell of corrosion products, causing a sharp drop in current, and failing to provide proper protection

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