What is the purpose of stress-relleved annealing?

In the processing of the precision parts, there are always some unsatisfactory places. Although we have the best processing machine, the best processing master and after processing everything is so perfect, after winning the machine into the quality control room or the next process, we found that the size of the product has changed quietly and the product becomes a unqualified product.

So how to avoid this kind of unqualified products? We need to use a very important process: stress-relleved annealing of steel pipe. Then we will introduce what is stress-relleved annealing and what is the purpose of stress-relleved annealing.

What is stress-relleved annealing?

The stress-relleved annealing is to heat the steel or all kinds of metal mechanical parts to a certain temperature for a period of time, then slowly cool down, so that we can get the heat treatment process which is close to the equilibrium state. In the mechanical manufacturing industry, annealing is usually used as a preparatory heat treatment process in the manufacturing process of the work piece. In the actual processing and production process, the application of the stress annealing process is more than that of the above. Hot forging, casting, cold deformation processing, cutting, welding, heat treatment, and machine parts assembly, without changing the microstructure, retained cold work, heat or surface hardening under the condition of low temperature heating of steel or machine parts, to remove all or part of the internal stress, deformation and cracking tendency of the decrease of the process, can be called to stress annealing. Due to the difference in the material composition, the processing method, the size and distribution of internal stress and the degree of removal, the temperature range of the stress annealing is very wide. Traditionally, the removal of stress at higher temperature is called stress relieving annealing. The treatment at lower temperature is called stress relief tempering. Actually, this two processes are almost same.

What is the purpose of stress-relleved annealing?

The internal stress in the finished parts is very harmful besides the size guarantee. If we do not remove it in time, the internal stress and the external loading force, that is, the superimposed force applied during the operation will cause the material to break accidentally. Therefore, casting, welding and cutting the work piece after machining should be carried out to stress annealing to eliminate internal stress generated in the process. So when you are always hard to do a good part, or your customers tell you the parts used in the process of accident off , you’d better consider taking the stress-relleved annealing process, this process will help you solve many problems.

Before placing the order, be sure to tell us the use of steel pipe, so that we can determine whether we need to take stress-relleved annealing or other processes.