Steel plate cold rolling oil should have been used as early as the 1930s. The early cold rolling lubricant used was water. Due to the insufficient lubrication ability of water and the serious corrosion problem, before World War II, cold rolling mills switched to using palm oil as rolling lubricant. Due to the limited resources of palm oil, people are constantly looking for new substitute materials, which has promoted the development of a large number of other organic materials including animal and vegetable oils and "substitute palm oil".
The oily component of "substitute palm oil" is an ester substance synthesized from polyhydric alcohols and saturated or unsaturated fatty acids such as C12~C18. These materials have excellent lubrication properties and can greatly improve the surface quality of cold-rolled sheets. However, as the rolling speed becomes higher and higher and the thickness of the steel plate gradually decreases, this type of lubricant has fatal flaws in cooling performance, thus emulsions were born, and emulsification technology developed accordingly.
Looking at the patent literature in recent decades, the composition of steel plate cold rolling rolling oil basically uses animal and vegetable oils, mineral oils, and synthetic esters as base oils, and is compounded with various other required functional additives, such as extremely Pressure agent, emulsifier, anti-rust agent, antioxidant and defoaming agent, etc.
Different types of rolling mills and rolling strips of different specifications have different requirements for cold rolling oil, and the composition of the rolling oil used is also different.
For tin-plated original plates and galvanized original plates with a thickness of less than 0.3mm in cold-rolled products, the ultra-thin plate cold rolling oil used is based on animal and vegetable oils and fats, fatty acid esters as oily additives, and phosphate esters. As an anti-wear agent, polymeric acid, synthetic ester, oxidized paraffin and other additives are added to improve its lubricity. Ultra-thin plate cold rolling oil can be used directly or recycled, and is characterized by good lubricity, but it usually requires a degreasing process before annealing.
For strips with a rolled product thickness less than 0.4mm, the cold rolling oil used is based on mineral oil, grease or synthetic ester, with additives similar to those used in ultra-thin plate cold rolling oil. With various functional additives such as surfactants. This type of cold rolling oil is characterized by the fact that the rolled strip directly enters the bell annealing furnace for annealing without degreasing. It is required that the residual oil attached to the surface of the steel plate does not contaminate the plate surface under annealing conditions, that is, the cold rolling oil is required to have Good rolling mill cleanliness and annealing cleanliness, but the lubricity requirements are lower than those of ultra-thin plate cold rolling oil, so it is suitable for circulation mode.
Development Trend of Cold Rolling Oil
The role of cold rolling oil in the cold rolling process is becoming increasingly obvious, and it is developing with the development of cold rolling technology and chemical raw material manufacturing technology. It is predicted that cold rolling oil will show the following development trends in the future.
1. Health and environmental protection
With the increasingly stringent environmental regulations and the continuous strengthening of people's environmental awareness, cold rolling oil is required to not only be practical, but also environmentally friendly and not harmful to the environment and the health of operators. This requires advances in refining technology and lubricant production technology to improve the performance of cold rolling oil base oil and additives and reduce the content of impurities and harmful substances.
2. Research and develop high-performance additives
In order to adapt to the development of cold rolling oil, functional additives with excellent performance need to be developed in the future, especially oily agents, polymer emulsification and dispersants, extreme pressure anti-wear agents and ashless anti-rust detergents.
The oily agents used in cold rolling oil tend to be synthetic esters with excellent performance, which have good lubrication and cleaning properties. While ensuring lubricity, their volatilization temperature should be reduced as much as possible in order to obtain an excellent annealed steel plate surface. . At present, the development trend of oil-based agents is to use complex esters of neopentyl polyol and C10~C16 mixed fatty acids.
The development trend of extreme pressure anti-wear additives for cold rolling oil is to develop high-sulfur additives with high sulfur content, low odor, low active sulfur content, good oil solubility, good anti-corrosion performance and environmental friendliness.
3. Develop multifunctional additives
Due to the competitive adsorption between polar molecules such as oily agents, extreme pressure agents, rust inhibitors, and emulsifiers on the metal surface, during the rolling process, the lubricity, extreme pressure anti-wear properties, and anti-wear properties of the cold rolling oil are important. Rust properties and annealing cleanliness interact and restrict each other. Therefore, it is necessary to develop additives with multiple functions to improve the performance of cold rolling oil.
4. Develop granularity control technology
In the future, the research on cold rolling oil will shift from macro to micro, such as studying the emulsification characteristics, particle distribution, charge state, thermal stability, chemical stability, hydrolysis stability, etc. of the emulsion after adding water. The use of polymer emulsification dispersants and emulsification technology with a special structure can keep the emulsion both large particle size and high emulsion stability, so that the cold rolling oil has good lubricity and cleanliness at the same time.
