Environmental protection and high efficiency corrosion inhibitor for inhibiting salt water corrosion on carbon steel, preparation method and use method thereof

Abstract

The present invention provides an environmental protection and high efficiency corrosion inhibitor for inhibiting salt water corrosion on carbon steel, a preparation method and a use method thereof, and relates to the field of chemistry. The corrosion inhibitor has characteristics of high efficiency, low cost, low toxicity and environmental protection, and is prepared through carrying out mixing stirring dissolving on 5-50% of a benzotriazole substance, 1-10% of benzoic acid and a salt thereof, 1-10% of molybdate, tungstate, phosphomolybdic acid and a salt thereof, and phosphotungstic acid and a salt thereof, 2-20% of an alcohol amine substance, 1-10% of an acid phosphate, 1-10% of a gluconate, 1-10% of an alkaline regulator, 1-10% of an oxygen scavenging agent and the balance of water. According to the present invention, the potassium dichromate or the sodium nitrite with high toxicity, and the non-environmental protection high phosphorus and high zinc can be replaced, and corrosion of calcium chloride salt water on carbon steel and copper can be significantly inhibited when the concentration of the corrosion inhibitor is 0.3-0.5%.

Description

technical field [0001] The invention relates to the field of chemistry, in particular to a novel high-efficiency environment-friendly corrosion inhibitor (SMT-BA) for inhibiting the corrosion of carbon steel in frozen brine (especially 30% calcium chloride solution) and its preparation method and use method. Background technique [0002] Calcium chloride brine has typical advantages such as low freezing point (the freezing point of 30% calcium chloride aqueous solution is lower than -50°C), low price, no flammability, high heat capacity, and good thermal conductivity. It has been used as frozen brine for nearly 200 years. Provide safe and reliable cold delivery for the process. However, calcium chloride brine is highly corrosive to steel. For example, it is uniformly corrosive to carbon steel, and the corrosion rate is generally 0.08mm / a. Generally, a large amount of corrosion leakage occurs in carbon steel pipelines that have been used for 2 to 3 years; and It is pitting a...

AI Technical Summary

Problems solved by technology

[0004] However, there are serious problems in the potassium dichromate type corrosion inhibitor: 1) Potassium dichromate belongs to the cationic oxidation type corrosion inhibitor, if the addition amount is insufficient, the coverage of the passivation film will be insufficient, and a higher corrosion rate will be formed between the non-covered part. Polarization potential, accelerated corrosion, which is common in chemical companies

And the corrosion inhibition rate is low, generally add about 1% to 5%, and the corrosion inhibition rate is around 80%.