Industrial paints and technical coatings applied to metals can perform functions that go far beyond providing an aesthetic finish. In manufacturing processes, they can be used to protect materials during processing, limit surface phenomena caused by high temperatures, isolate selected areas during heat treatment, or enable component marking and traceability. Selecting the most suitable solution therefore depends on the type of metal, process temperature, manufacturing operation and function required from the coating. There is no universal industrial paint: different formulations are developed to meet specific operating conditions and technical objectives.
ATP Europe provides coatings and technical products for a wide range of metalworking processes. Below, we look at the main types of industrial paints and functional coatings, how they differ and which criteria should be considered when selecting the most appropriate solution.
What are industrial paints?
The term industrial paints covers a broad range of products applied to surfaces to provide specific aesthetic, protective or functional properties. In metalworking, however, a coating can become an integral part of the manufacturing process rather than simply a finish applied to the completed component. A technical coating can, for example, create a temporary barrier during heating, prevent a selected area from being affected by a thermochemical treatment, reduce friction between metal and tooling, or allow a component to remain identifiable even after high-temperature processing.
For this reason, in industrial applications it is often more accurate to refer to functional coatings for metals. The keyword “industrial paint” actually covers a much wider range of products than conventional paints used solely to colour or protect a surface.
What are industrial paints for metals used for?
The function of the coating should be defined before selecting the formulation itself. Depending on the process, an industrial paint for metals can meet very different requirements.
Protection during high-temperature processing
When metals are exposed to high temperatures, phenomena such as oxidation and, in the case of certain steels, decarburization may occur. Specific protective coatings for metals can create a barrier between the surface and the process atmosphere, limiting surface alterations during heating. This function is particularly important in processes such as forging, rolling, preheating and other hot-working operations, where the surface quality of the component can affect subsequent manufacturing stages.
Selective masking during heat treatments
Some coatings are used not to protect the entire component, but to isolate selected areas only. This is the principle behind Stop-Off coatings, which are used during heat and thermochemical treatments when certain surfaces need to be excluded from the treatment. These formulations are used, for example, in carburizing, gas nitriding and ion nitriding processes. The coating is applied to the areas that need to retain different characteristics from those exposed to the treatment.
Lubrication and friction reduction
In other industrial processes, the primary function is not to provide permanent surface protection, but to support the processing of the material. During metal forging, for example, specific forging lubricants can help control friction and improve processing conditions at high temperatures. In this case, simply referring to the product as an industrial paint would be misleading: it is applied to the surface, but its function is closely linked to the dynamics of the manufacturing process.
Release and non-stick properties
Another family of technical coatings is represented by boron nitride coatings. The properties of boron nitride make it suitable for different metalworking processes where lubrication, release performance and high-temperature behaviour are required. Applications of this type can be useful in casting, forming, pressing and other processes where the interaction between metal, tooling and working surfaces needs to be controlled.
Component marking and traceability
Metal marking paints, on the other hand, perform a different function: they enable components to be identified and traced throughout the various stages of the production cycle.
In these applications, the formulation must be selected according to the material, the temperatures reached and the processes the component will undergo, so that the marking maintains the required characteristics throughout the process.
Industrial paints and technical coatings: the main types
The different functions described above demonstrate why not all industrial paints for metals should be considered equivalent. A more useful classification begins with the objective of the process.
- protective coatings, used to limit surface phenomena during heating and high-temperature processing;
- Stop-Off coatings, designed for selective protection during specific heat and thermochemical treatments;
- lubricating coatings, used to control friction and processing conditions;
- non-stick and boron nitride coatings, used in different casting, forming and hot-working processes;
- marking paints, designed for component identification and traceability.
These families are complemented by technical products that should not strictly be classified as paints. One example is borosilicate glass for extrusion, which is used as a lubricating solution in hot extrusion processes. Maintaining this distinction is important when identifying the most suitable technology for a specific manufacturing operation.
How to choose an industrial paint or technical coating
The selection of an industrial paint should not begin solely with the type of product, but with the conditions in which the coating will be required to perform. Material, temperature, process and required function must all be considered together.
- Type of metal: Carbon steels, stainless steels, titanium alloys, aluminium, nickel alloys and other materials react differently to process temperatures and atmospheres. A formulation suitable for one metal therefore cannot automatically be considered appropriate for every other material.
- Process temperature: In high-temperature processes, it is necessary to consider not only the maximum temperature reached, but also exposure time and the conditions to which the coating will be subjected. These factors can require significantly different coating characteristics and formulations.
- Type of process: Forging, extrusion, heat treatment, casting and marking all involve different requirements. Correct selection should therefore begin with the industrial process in which the product will be used.
- Function required from the coating: It is also essential to establish exactly what the coating needs to do: protect against oxidation, prevent the diffusion of specific elements, reduce friction, facilitate release or ensure that a marking remains legible.
Only by considering these parameters together is it possible to identify a solution that is consistent with the process, rather than selecting an industrial paint solely on the basis of generic product characteristics.
Industrial paints in different manufacturing sectors
Technical coatings are used in numerous sectors where metals are exposed to particularly demanding conditions. Requirements can, however, vary significantly from one industry to another.
- Forging: In forging, products applied to the surface can contribute to material protection and friction control during high-temperature processing. Protective coatings and lubricants therefore meet different but complementary requirements.
- Heat treatment: In the heat treatment sector, coatings used to control surface modifications or selectively mask specific areas of a component are particularly important.
- Foundries: In foundries and casting processes, solutions may be required to promote release and limit interaction between molten metal and the surfaces with which it comes into contact. Specific boron nitride coatings are also used in this field.
- Titanium and the aerospace industry: The processing of titanium alloys and materials intended for the aerospace industry requires particular attention to process conditions, especially when components are exposed to high temperatures. Surface protection and control of interactions with the surrounding atmosphere therefore become key factors in coating selection.
How are industrial paints applied?
The application method depends on the characteristics of the product, the geometry of the component and the organisation of the manufacturing process. Available techniques include brush application, spraying, dipping and flow or curtain application systems.
Individual methods are not examined in detail here because selecting the application technique is a separate issue from selecting the formulation itself. To learn more about the characteristics and differences between these techniques, see our guide to industrial painting and application methods. If, on the other hand, you want to explore the complete process, from surface preparation through to coating drying, you can find more information on the page dedicated to metal painting.
ATP Europe solutions for metal processing
Protection and processing requirements vary significantly depending on the material and manufacturing process. For this reason, ATP Europe offers different product families developed for specific industrial applications, ranging from protective coatings and Stop-Off systems to lubricants, boron nitride coatings and marking paints. For a complete overview of the available technologies and their characteristics, visit our page dedicated to ATP paints and coatings for metals. Selecting the right solution always begins with an analysis of the actual operating conditions. Material, temperature, process and required result must be assessed together in order to identify the most suitable coating and application method.
Do you need to identify an industrial paint or technical coating that is compatible with your production process? Contact ATP Europe to tell us about your application and evaluate the most suitable solution together.