What is welding?

It is usually a combination of two or more elements. After heating them to high temperature and consolidating them. These are, for example, metals or plastics. Thanks to this treatment, we have a hard structure that holds the material firmly. During this process, additional filler (e.g., tin) is often added between the fragments to be joined.

What are the types?

•    Laser
•    Electric
•    Hybrid
•    Termite
•    Gas
•    Connecting methods

Electric welding:

With the use of a welding machine based on the phenomenon of an electric arc at temperatures up to 4000 ° C, it is used to weld metal sheets with a thickness of 1 mm to 80 mm. Welding can be done with amateur small equipment or with specialized welding machines in industrial and production systems.

Basic methods of work in welding:

• Arc non-consumable electrode (TIG)
• Gas shield (MIG / MAG)
• Stick electrodes (MMA)
• Covered arch

Why is electric welding the most popular?

• Low costs
• It fits easily
• High availability of devices

What is laser beam welding (LBW)?

It is a technique of thermal joining metals (or plastics) with a laser. It involves deep penetration. It is the main welding technique in structural applications.

How does it look in practice?

The laser beam is focused and aligned to the surface or a spot just below the material thickness. Extremely high energy density (> 106 W / cm2) of the concentrated beam, blends the contact area of the joined surfaces.

Which method is recommended for thinner, high-strength and abrasion-resistant steel?

The answer is laser. The most important thing is that the weld has the material properties as close as possible to the base metal. It is possible to add wire as filler - cold or inductively heated to reduce thermal effects.

Benefits:

• Possibility to weld steel in various grades and dimensions
• Low thermal deformation, i.e. excellent flatness
• High efficiency
• Outstanding mechanical properties
• A very narrow HAZ zone
• Very good abrasion properties
• Long and wide sheets with individual choice of thickness and properties
• Cost effectiveness compared to traditional methods

Weaknesses:

• Limited material thickness (max. 25 mm in hybrid welding)
• High investment cost compared to traditional methods

Thermite (aluminothermal) welding

An exothermic process in which the source of heat is a chemical reaction consisting in the combustion of thermite, i.e. a mixture of iron oxide (metallurgical scale) and aluminum in a ratio of 78:22.

It is used to repair:

• Foundry defects
• Broken shafts
• Railway rails
• Steel, cast steel and cast iron items with large sections

What does the merge process look like?

First form the parts leaving a gap.
The molding mass must be fired and dried. It should be heated to 800 ÷ 1000 ° C with a propane-butane burner.
Place the termite in the crucible and ignite with flash fires with an ignition temperature of approximately 1300 ° C.
After burning, the obtained steel is heated to the temperature of approx. 2500 ÷ 2900 ° C.
Molten metal is poured into the mold.
During contact with the joined surfaces, the edges are melted and permanently bonded.
After cooling down, the mold is removed, the lugs are cut and ground is ready.