Gaps may form between the surface of stainless steel pipes and deposits due to equipment and component structures or the presence of metal or non-metallic deposits. This can lead to punctate and ulcerative damage caused by crevice corrosion when exposed to corrosive media. In the presence of water-based media, such as Cl-, the medium solution in the gap becomes more acidic (increased Cl- concentration, decreased pH value) and lacks oxygen (oxygen concentration difference battery, lack of oxygen in the gap).
How To Prevent Gap Corrosion of Stainless Steel Pipe?
1. The most fundamental way to eliminate gap corrosion is to avoid the existence of gaps in structural design, and take corresponding measures to prevent the gaps between the heat transfer equipment tubes and the tube sheets, and the gaps between flanges, washers, bolts, and rivets.
2. To prevent the accumulation of dirt, including marine organisms, on the surface of stainless steel pipes, it is important to clean them regularly and maintain a flow rate of at least 1.5m/s in seawater and other environments.
3. For protection against crevice corrosion, it is recommended to use stainless steel pipes with high levels of chromium, molybdenum, and nitrogen.
In general, solving crevice corrosion is more challenging than solving pitting corrosion, and it incurs higher economic costs. Model selection is particularly difficult in this regard.
Post time: Dec-27-2023