What is welding?

What is welding?

It is a combination of usually at least two elements. Through heating them to high temperatures and fusion. These include, for example metals or plastics. Thanks to this treatment, we have a hard structurewhich holds the material firmly in place. During this process, additional filler (e.g. tin) between the fragments to be joined. 

What are the types? 

1. Laser; 
2. Electrical; 
3. Hybrid; 
4. Thermite; 
5. Gas; 
6. Combining 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-melting electrode (TIG); 
• Gas shielding (MIG/ MAG); 
• Covered electrodes (MMA); 
• Covered bow. 

Why is electric welding the most popular?   

• Low costs; 
• Easy to adjust; 
• High availability of equipment. 

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? 

Laser beam is focused and aligned evenly to the surface or a spot slightly below the thickness of the material. The extremely high energy density (> 106 W / cm2) of the focused beam, superheats the contact area of the surfaces to be joined.  

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

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

      Benefits: 

• Steel can be welded in a variety of grades and dimensions; 
• Low thermal deformation, i.e. excellent flatness; 
• High efficiency; 
• Excellent mechanical properties; 
• Very narrow HAZ; 
• 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 welding (aluminothermic) 

Exothermic process in which the heat source is a chemical reaction involving the combustion of thermite, a mixture of iron oxide (steel mill scale) and aluminium in a ratio of 78:22. 

It is used to repair: 

• Casting defects; 
• Cracked shafts; 
• Railways; 
• Steel, steel and cast iron objects with large cross-sections. 

What does the merge process look like? 

First form the parts leaving a gap.  

The moulding compound must be fired and dried. It must be heated to a temp. 800 ÷ 1000°C with a propane-butane burner.  

Place termite in a crucible and ignite using instant ignition with a flashpoint of approx. 1300 °C.  

After combustion, the result is steel heated to a temperature of approx. 2500 ÷ 2900 °C.  

Molten metal is poured into the mold.  

During contact with the surfaces to be bonded, the overmelt edges and durable combination.  

Once cooled, it is removed form, cuts off the lintel and grinds it on the ready.