The processing of stainless steel as a material has a number of features. This also applies to welding parts.
Stainless steel welding is not an easy job. It requires the contractor to strictly adhere to the process. The metal compound 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 forms, which must subsequently be removed. Basically, stainless steel is welded with a constant current source using tungsten electrodes.
The stainless steel contains chromium, which, when processed by fire, forms a chemical compound of carbon and chromium, violating the structuralization of steel and increasing its brittleness.
Actually, this reason forced us to weld a stainless steel in a protective 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 matter. If the elements to be welded are thicker than one and a half millimeters, arc welding is used, which is carried out manually by non-consumable electrodes of refractory tungsten. This process must take place in the protective atmosphere 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 a stainless steel,
an inert gas does not combine with the metals of the elements being welded.
A stainless steel tank or thin-walled stainless steel pipes cannot be welded manually.
To connect elements whose thickness is less than 1 mm, pulsed welding with a consumable electrode in a neutral gas environment is used.
Steel material with a thickness below 0.8 mm is welded by an electric arc with metal transfer by jet.
Together with the two classical methods of stainless steel processing described above, high-frequency, laser, and other methods of welding are widely used.
The method of joining parts is selected based on the composition of the metal and its thickness.
There are a number of features for welding stainless steels. And if they are not taken into account, then the weld will be defective. For example, after welding, corrosion may form in the weld area, which experts call “knife”. And with prolonged exposure to high temperatures, the seam may burst.
By choosing the correct filler materials and arc length, “hot cracks” can be prevented.
When the welding of the stainless steel is completed, the finished seams are treated with abrasive materials, grinding and grinding them.
Then heat treatment is carried out . In this case, third-party mixtures melt, and chrome spreads evenly throughout the seam.
To clean the weld from dirt and plaque, etching agents are used. This procedure also ensures that the joint does not rust in the future.