Factors Affecting the Corrosion Resistance of Stainless Steel T

• Posted by Yin Tuo April 29, 2021 - Filed in Other - #stainless steel seamless pipe  - 862 views

   

  The production of stainless steel seamless pipe is divided into cold processing and hot processing. No matter which processing technology is used, it will have a certain impact on the stainless steel pipe. Causes of cold working damage to the corrosion resistance of stainless steel pipes and related factors:

  1. Cold working such as cold drawing and cold rolling will cause cold work hardening of stainless steel, especially austenitic stainless steel, and induce lattice dislocation, martensitic transformation, carbide precipitation, increase in magnetism and residual stress, thereby making it resistant Corrosion performance is reduced. Annealing or solution heat treatment after cold working can effectively eliminate these adverse effects. Therefore, austenitic stainless steel seamless steel pipes and cryogenically processed stainless steel welded steel pipes must be supplied in a solid solution or annealed state to effectively ensure their corrosion resistance.

  2. In addition to stress corrosion cracking and the environmental conditions where there is a risk of corrosion fatigue due to alternating stress, controlling the degree of cold working is another way to avoid its adverse effects. This is particularly important for processing operations that are locally cold worked such as cold bending and cold expansion and are difficult to be annealed.

  3. For elbows that require stress corrosion cracking resistance, such as U-shaped austenitic stainless steel elbows for heat exchangers that work under high temperature and high-pressure water or steam conditions, no matter the radius of the cold bend, it must be effective after the cold bend. Stress relief annealing treatment.

  4. 06Cr19Ni11Ti(321) stainless steel has better resistance to stress corrosion cracking than 316L and is a more suitable austenitic steel pipe material for U-tube heat exchangers.

  5. The cold twisted stainless steel tube can constitute a new type of heat exchanger with a compact structure and higher heat exchange efficiency, which is worthy of attention and exploration and development by relevant design and application departments.

  6. After the U-shaped duplex stainless steel is cold-formed or twisted, it is not suitable or should not be subjected to partial stress relief annealing.

  7. The resistance heating method is more energy-saving and time-saving than the indirect heating method in the furnace and is a local stress-relieving heat treatment method that is easy to realize automatic control.

  If you are interested in our ferritic stainless steel seamless pipe and tube and other stainless steel seamless pipes, you can contact Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. at any time.