What is stress relief?

The reason why alkali pipelines require stress relief at a certain concentration may be to avoid pipeline embrittlement. The stress can be eliminated after the metal pipeline is annealed.

When two metals are in contact, stress concentration will occur. Stress concentration is very harmful. It is hundreds or even thousands of times the stress in places without stress concentration, so stress relief must be carried out. For example, the welding point between two pipes is where the stress is concentrated. Stress relief can be achieved by heat treatment. You can refer to relevant mechanical information to understand stress concentration.

Stress definition: Stress: When a material cannot be displaced under the action of external force, its geometric shape and size will change. This deformation is called strain. When the material deforms, an equal but opposite reaction force is generated internally to resist the external force. The concentration of distributed internal forces at a point is called stress, and the product of stress and micro area is micro internal force. Or when an object deforms due to external factors (force, humidity changes, etc.), an internal force interacts between various parts of the object to resist the action of such external factors and strive to return the object from the deformed position to the position before deformation. How to eliminate: 1 Change the direction of the pipeline and artificially add L-shaped, Z-shaped, and π-shaped layouts. 2. Change the pipeline restraint form (fixed bracket, guide bracket), and it is really impossible to consider spring brackets. 3. When space does not allow, or it is calculated that the passage cannot pass, bellows or expansion joints can be added. When improving restraint by adding bellows or expansion joints, be careful not to use them in situations where stress is alternating.