Analysis of the quality objection of [304 stainless steel pipe stress corrosion failure]
The industrial application of stainless steel pipe is mainly used in the fluid industry. If the steel pipe is corroded and damaged, it will cause serious losses. This kind of thing happened to a customer.
The customer purchased a batch of 304 stainless steel pipes for steam condensation and reflux. The application environment of this batch of steel pipes requires the steel pipes to be buried in the ground, but after half a year of use, cracking and leakage problems occurred, affecting the overall use, so the customer raised a quality objection.
After an on-site inspection by the suppliers’ technicians, it was identified as transcrystalline stress corrosion cracking.
Although 304 stainless steel will corrode in certain environments, the corrosion rate in the soil is very low, especially when stress corrosion cracking occurs in just six months, this phenomenon is even more abnormal. Because stress corrosion cracking must have a medium that induces pitting corrosion, such as a chloride-containing or sulfur-containing environment, and there must be tensile stress.
Then why does stress corrosion cracking occur here? Is there a corrosion environment? After observation, part of the leaked pipeline line crosses a highway, and the city generally uses antifreeze salt to melt the snow after it snows in winter. The antifreeze salt dissolves and penetrates into the soil where the pipeline is located, and the pipeline has thermal expansion and cold The shrinkage stress exists, which eventually leads to stress corrosion cracking.
The reason for this case is that the use environment of stainless steel has not been fully considered, so pipes of other materials should be replaced, or protection measures should be strengthened on the side of the pipeline near the road.