What is cold welding
With respect to metallic materials, cold welding refers to the process of joining two workpieces at room temperature. The strength of the joining is somewhat close to “normal” welding, the joining is permanent and can usually only be reversed by damaging the workpieces.
What happens during cold welding?
Stainless steel products can be joined together under great pressure. The pressure causes a cold welding of the two materials. The prerequisite for this is the plasticity of the materials. The materials are permanently deformed under the impact of the force applied (as opposed to flexible or brittle materials). In case of cold welding, the materials (e.g. combinations of stainless steel) are joined together. The cause for cold welding is the strong attractive force between two materials with very flat surfaces. In the case of these two materials, an exceptionally high number of metal atoms touch each other at the interfaces so that there is a high force of attraction as a result. This is especially the case for bodies with very similar material composition.
Solutions against cold welding
Depending on their area of application, different solutions are imaginable. Thus, cold welding can be excluded due to certain combinations of materials. This is the case with materials made of bronze and steel, for instance. Lubricants are frequently used as well to prevent welding under pressure. However, it is not always possible to use material combinations for which cold welding can be excluded. Lubricants, on the other hand, are often incompatible with elastomeric materials. They can damage seals, for example. When using stainless steel or rustproof steel, the BORINOX® PROCESS FOR THE HARDENING OF RUSTPROOF STEEL is suitable. It reduces the cold welding potential and is particularly useful if the positive properties of stainless steel cannot be dispensed with.