Water Displacing Rust Preventive oils: green solution in metal working industry

Corrosion is the deterioration of metal materials caused by chemical, electrochemical, or physical dissolution from surrounding corrosive media such as chloride ions, water, and oxygen. Every year, the economic losses are estimated to account for approximately 3% to 4.5% of the gross national product due to metal corrosion.

 

Mechanism and Challenges of Rust Preventive Oils

Rust preventive oils can isolate metal surfaces and the environment, protecting metals from corrosive media attack.

The conventional rust inhibitors on the market are facing the following challenges: the workpiece has a high requirement for cleanliness and dryness. But the preventive oil films are uneven and have poor resistance to humidity and salt spray, which is toxic and hazardous to environmental.

With the growth of environmental awareness, several developed countries have banned barium sulfonate salts. Therefore, the formulation of water-displacing rust preventive using environmentally friendly corrosion inhibitors has gained increasing attention.

 

Working Principle of Water-Displacing Rust Preventive Oils

 

Water-displacing rust preventive oils contain strong polar groups that can adsorb strongly on the metal surfaces. The non-polar long-chain hydrocarbon groups provide hydrophobic and water-repellent functions. Most oil-soluble rust inhibitors are organic polar compounds with polar groups and long carbon chains, and many of them have water-displacing properties.

When metal parts covered with a water film are immersed in corrosion inhibitor oil, the water film on the metal surface is displaced by the oil film, achieving both dewatering and rust prevention in a single step.

 

Water-Displacing Rust Preventive Oil: A "Green" Solution for Metal Corrosion Protection?

Environmental Problems with Traditional Corrosion Inhibitors

Barium sulfonates are the earliest and most widely used oil-soluble corrosion inhibitors. Due to the health and environmental hazards of barium salts, and with increasingly stringent environmental regulations, several developed countries have begun phasing out barium sulfonates.

 

Advantages of Water-Displacing Rust Preventive Oils Calcium-Based Agents

• Low toxicity, safe for humans and the environment:

Eco-friendly water-displacing rust preventive oils are non-toxic and environmentally safe. No offensive odor during prolonged use and do not irritate the skin, minimizing impact on both operators and the environment.

• Energy savings and reduced consumption:

Water-displacing rust preventive oils can be used at ambient temperatures, and there is no need for heating or drying, which significantly reduces energy consumption and carbon emissions.

• Easy to clean and low secondary pollution:

The oil films formed by eco-friendly rust preventive oils are thin and transparent films that are easily removed with solvents or alkaline cleaners, reducing chemical consumption and wastewater treatment burdens during the cleaning process.

 

Comparison of Different Rust Inhibitors

 

Demulsibility Performance Comparison

 

Calcium sulfonate exhibits poor demulsibility and is prone to decomposition in the presence of water. The water-displacing capability and calcium-binding affinity of oxidized paraffin-based compounds are superior to those of sulfonate-based alternatives.

 

Salt Spray Corrosion Resistance Comparison

 

The calcium-based composite agent demonstrates demulsibility comparable to barium sulfonate while offering superior salt-spray corrosion resistance. It's safe and non-toxic and can serve as an effective drop-in replacement for barium sulfonate and an eco-friendly corrosion inhibitor in water-displacing rust-preventive oil formulations.

 

Chorus offers a wide range of rust-preventive additives for lubricants and metalworking fluids, including the water-displacing rust-preventive oil additive Chorus-2100. Chorus-2100 is a rust-preventive additive package that is designed for blending water-displacing anti-rust oils and protecting metal parts during manufacturing, assembly, and storage.

 

It is calcium sulfonate-based, eco-friendly (barium-free), and has excellent salt spray performance, fast water displacement, and easy blending. Rust preventive oil Chorus 2100 is suitable for precision parts machining, mechanical processing, and various industries; it can meet rust protection requirements across different rust protection periods.

 

In addition, Chorus offers other rust inhibitor additives, including dinonylnaphthalene sulfonate-based rust inhibitors, coolant corrosion inhibitors, and multi-metal corrosion inhibitors, meeting the anti-corrosion needs of diverse application scenarios.

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