Stainless steel welding

Processing stainless steel, as a material, has a number of features. This also applies to welding parts.

Stainless welding is not an easy job. It requires the performer to strictly observe the technological process. The area of connection of metals must be protected from the negative influence of atmospheric air. Having satisfied this condition, we will ensure the reliability of welding.

In many ways, high-quality welding of stainless steel depends on the correct cutting of the edges of the welded components and the preparation of electrodes.

As a result of hot working of the parts, that is, their welding, an oxide film is formed, which must be subsequently removed. In general, stainless steel welding is produced by 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, which breaks the structuring of steel and increases its fragility.

Actually, this reason also forced welding of stainless steel in the environment of protective gases and using specially selected fluxes.

Welding methods

To connect parts from stainless steel, any type of welding can be used. There is an unspoken rule in this matter. If the welded elements are thicker than one and a half millimeters, arc welding is used, carried out manually by non-consumable electrodes made of refractory tungsten. This process must take place in the protective environment of any of the inert gases. Such gases are stable, do not support combustion and do not form products of chemical reaction with other materials. When welding stainless steel, the inert gas does not combine with the metals of the welded elements.

A stainless steel tank or thin-walled stainless steel pipes can not be welded by a manual arc method.

To connect elements whose thickness is less than 1 mm, pulsed welding with a consumable electrode in a neutral gas medium is used.

Steel material with a thickness of less than 0.8 mm is welded by an electric arc with metal transfer by the jet.

Together with the two classical methods of processing stainless steel described above, high-frequency, laser and other methods of welding are widely used.

The method of joining parts is chosen based on the composition of the metal and its thickness.

There are a number of features of welding stainless steels. And if they do not take into account, the welded seam will turn out to be defective. For example, after welding in the seam area, corrosion can be formed, which experts call "knife". And with prolonged exposure to high temperatures, the seam can burst.

Correctly selecting filler materials and arc length, "hot cracks" can be prevented.

When the stainless steel is finished, the finished seams are treated with abrasive materials, grinding and polishing them.

Heat treatment is then carried out . At the same time, extraneous mixtures are melted, and chromium spreads evenly throughout the seam.

Etching agents are used to clean the weld seam from dirt and plaque. This procedure also ensures that the seam will not rust in the future.