Processing stainless steel as a material has a number of features. This also applies to welding parts.
Welding stainless steel is not an easy job. It requires the contractor to strictly adhere to the technological process. The metal bonding area must be protected from the negative effects of atmospheric air. By fulfilling this condition, we will ensure the reliability of welding.
In many ways, high-quality stainless steel welding depends on the correct cutting of the edges of the components to be welded and the preparation of the electrodes.
As a result of hot processing of parts, that is, their welding, an oxide film is formed, which must subsequently be removed. Basically, stainless steel welding is performed by a constant current source using tungsten electrodes.
Stainless steel contains chromium, which, when treated with fire, forms a chemical compound of carbon and chromium, which disrupts the structuring of steel and increases its fragility.
Actually, this is the reason that forced weldingstainless steel in a shielding gas environment and use specially selected fluxes.
Welding Methods
Any type of welding is suitable for joining stainless steel parts. There is an unspoken rule in this case. If the elements to be welded are thicker than one and a half millimeters, arc welding is used, which is carried out manually with non-consumable electrodes made of refractory tungsten. This process must take place in a protective environment of any of the inert gases. Such gases are stable, do not support combustion and do not form chemical reaction products with other materials. When welding stainless steel, inert gas does not combine with the metals of the elements to be welded.
A stainless steel tank or thin-walled stainless steel pipes cannot be welded by manual arc welding.
Members less than 1 mm thick are joined by pulsed consumable electrode welding in neutral gases.
Steel material with a thickness below 0.8mm is welded by an electric arc with metal transfer.
Together with the two classical methods of processing stainless steel with fire described above, high-frequency, laser and other welding methods are also widely used.
The method of connecting parts is selected based on the composition of the metal and its thickness.
There are a number of features of stainless steel welding. And if they are not taken into account, then the weld will turn out to be defective. For example, after welding, corrosion can form in the area of the seam, which experts call “knife corrosion”. And with prolonged exposure to high temperatures, the seam may burst.
By choosing the right filler materials and arc length, "hot cracks" can be prevented.
When stainless steel welding is finished, the finished seams are processed with abrasive materials, cleaning and grinding them.
Then heat treatment is carried out. In this case, third-party mixtures are melted, and chrome is distributed evenly throughout the seam.
To clean the weld from dirt and plaque, pickling agents are used. This procedure also ensures that the seam will not rust in the future.
