What is welding: definition and main methods
Welding represents one of the main metal processes in the metalworking and manufacturing industry. It is the process of permanently joining two or more metal parts through the action of heat, pressure, or both, with or without the addition of external material. Over the years, welding techniques have evolved to include such solutions as electric arc welding (MIG/MAG, TIG), resistance welding, laser welding, ultrasonic welding, and many others.
These methods, chosen according to the type of metal, thickness and application area, now make it possible to achieve joints that are strong, durable and, in many cases, almost indistinguishable from the source material. However, reaching high temperatures and contact with atmospheric oxygen expose the materials to specific risks, making protection through dedicated coatings essential.
Challenges in welding: decarburization, oxidation, wear and tear
One of the main problems associated with welding is decarburization, which is the loss of carbon from the surface layers of steels due to the high temperature and oxidizing environment. Decarburization results in a loss of hardness, mechanical strength and, in the long term, a reduction in the service life of components. At the same time, surface oxidation generates slag and films that hinder the adhesion and quality of the welded joint.
Another aspect not to be taken lightly is the formation of slag and spatter during welding: these residues, if not properly managed, can lead to structural imperfections and require laborious post-process cleaning. Finally, high temperatures and repeated thermal cycling accelerate wear and surface alteration phenomena, impacting the functionality and appearance of metal fabrications.
Overlay welding and types of protective coating
Precisely in response to these issues, the technology of overlay welding (cladding), or the controlled deposition of a protective layer on the metal surface, has been developed. This layer can consist of high-strength metal materials (nickel, cobalt, special alloys) or special protective coatings that prevent oxidation and decarburization.
Today there are several protective coating solutions, such as those proposed by ATP Europe, designed to be easily applied, ensure optimal adhesion, withstand high temperatures, and-key element-be able to be removed without leaving harmful residues or compromising the surface quality of the metal.
Comparison of coatings: MIG, PTA, laser and others
Coated welding technologies differ in principle of operation, results obtained and type of application. In the case of MIG (Metal Inert Gas) welding, for example, an inert gas is used to protect the welding zone from oxygen and contaminants, but the addition of specific coatings further increases surface protection and joint quality. Cladding by the Plasma Transferred Arc (PTA) process allows very thin layers of special alloys to be deposited with very high adhesion and strength, while laser welding reduces the thermally altered zone, providing very precise joints with very little deformation.
Regardless of the technology, the use of a suitable coating drastically reduces the need for rework, improves protection against chemical and physical agents, and optimizes the aesthetic and functional performance of the part.
How to choose the right coating for the metal type
Not all coatings are suitable for every type of metal. In the case of carbon steels, it is essential to favor products that prevent decarburization and surface oxidation. For stainless steels, on the other hand, you need a coating that protects not only against oxidation but also against the risk of cross-contamination that could compromise corrosion resistance.
An ideal coating for welding must withstand temperatures that can exceed 1,000°C, adhere perfectly even to complex geometries, create no slag, be easily removable, and leave no residue. It is with this in mind that ATP products have established themselves as the industry benchmark for metal protection in welding and heat treatment processes.
ATP protective coatings for welding: solutions from ATP Europe
Choosing the right coating for welding depends on the type of protection you want to achieve on the metal: avoiding splash damage, improving lubrication, or actively protecting the workpiece from oxidation and decarburization at high temperatures.
Boron nitride lubricants and release agents: ATP-R12, ATP-R10B2, ATP-R20
Products such as ATP-R12, ATP-R10B2 and ATP-R20 are boron nitride and water-based lubricants developed to protect metal surfaces from the adverse effects of weld spatter and facilitate hot forging and stamping operations. These coatings are not formulated to protect against decarburization and oxidation, but are essential to reduce melt deposition, prevent slag adhesion, and prolong the life of tools and surfaces exposed to intense thermal cycling.
ATP-R12 is presented as a lubricating paste with excellent thermal stability (withstands 900°C in oxidation, up to 1300°C in reducing atmosphere), long service life and excellent spreadability. It can be applied by brush, dip, spray or rain, to metals such as steels, copper and their alloys, glass, ceramics and graphite.
ATP-R10B2 is distinguished by its blue coloration that facilitates visual verification of coverage. Also boron nitride-based, it protects surfaces up to 1200°C, offers excellent lubrication and is used especially where clear distinction of treated areas is required.
ATP-R20 is designed for the protection of metals, glass, ceramics, composite materials and plastics. It boasts wide application versatility, resistance to 900°C in oxidation and 1300°C in a reducing environment, and can be used with different application systems (brush, dipping, spray, spraying).
ATP protective ceramic coatings: the solution against oxidation and decarburization
If the priority is to protect metals from oxidation and decarburization during heat treatments or welding, then protective ceramic coatings developed by ATP Europe are the right choice.
These ceramic coatings are water-based, solvent-free, non-toxic formulations specifically designed to protect common steels, specialty steels, stainless steel, titanium, super alloys and other high-performance metals. They create an effective, adherent barrier that prevents the diffusion of oxygen and the escape of alloying elements from the metal, blocking decarburization and oxidation processes even under extremely high temperature conditions.
Main features of ATP ceramic coatings:
- Active and durable protection against oxidation and decarburization up to temperatures typical of the most critical heat treatments and welds.
- Versatile application: they can be applied by brush, dip, spray, or flow coating to suit any geometry or production requirement.
- Safe and environmentally friendly: they are water-based, non-flammable and do not release toxic substances during use.
- Customizable formulation: ATP can tailor the formula according to the type of metal, production process and result required.
These coatings are ideal for both the treatment of individual high value-added components and for large-scale applications, such as in the production lines of foundries, machine shops, and advanced component industries.
Where to use ATP ceramic coatings:
They are recommended wherever there is a need to limit surface oxide formation and prevent carbon loss:
- Prolonged heat treatments
- High-temperature welding processes
- Production and processing of high-alloy steels
- Applications on titanium, superalloys, nickel alloys, cast iron, copper, aluminum, special alloys
Choosing the right coating: why it pays to invest in professional protection
In the world of industrial welding, the quality of the protective coating makes the difference between an efficient production process and the need for constant rework. A high-quality coating not only preserves the mechanical properties and strength of metals, but also drastically reduces downtime due to cleaning, rework, and replacement of damaged parts. ATP Europe’s long experience in the field of protective coatings and its continuous quest for improvement and innovation make these coatings the best choice for anyone who wants to get the best out of their machining operations.
Another distinguishing feature of ATP Europe is its ability to support the customer not only in the selection of the most suitable product, but also in the testing and optimization phases of the application process. Thanks to a highly specialized technical team, ATP is able to offer personalized advice, studying together with the client company the specific production needs and suggesting the best protection strategy for its welds.
To discover the solution best suited to your needs, receive qualified technical assistance or request a sample, contact ATP Europe now: our team is at your disposal to accompany you towards uncompromising welding!