The stainless steel represents a material that can be characterized as an iron-based metal alloy with less than 12% chromium. It has a resistance to rust thanks to a protective outer layer of chromium oxide, but the term ‘stainless steel‘ does not identify a specific metal type and cannot be used for any purpose. Here is a quick guide on how to solder some types of stainless steels.
Austenitic stainless steels
These steels They are generally the most weldable because they have a low thermal conductivity and a high coefficient of expansion compared to the others. stainless steels. These properties result in high material distortion when welding and require specific strategies, including a low carbon base metal, a titanium or niobium base metal, or a heat treatment solution.
Ferritic stainless steels
They identify the stainless steels ferritic because of their ferromagnetism and inability to be hardened by heat. These stainless steels They are welded with austenitic or ferritic material and by means of arc welding. Heat treatment may be required after welding
DUPLEX stainless steel
The stainless steels containing a mixture of austenitic and ferritic are called duplex steels. The most important factors when welding these types of steels they are to limit the time (take as little time as possible) and also limit the temperature between 300 and 980°C in order to avoid the loss of properties of these materials.
The martensitic steels They are characterized by their magnetism and by their ability to be fully hardened by heat. These steels they are not easily weldable. Best results can be achieved with metals with low carbon content and heat treatment before and after welding.
hardenable stainless steels
The stainless steels hardenables are easily welded if the proper heat treatment is performed.
Below we will find the table with the chemical compositions of the different stainless steels: