The stainless steel 316L was severely corroded after being used for less than 2 months

What kind of material is it? 316L also has many other classifications. Was the wrong choice made?

What medium is it traveling on? How high is the temperature? What’s the pressure?

It is necessary to check the condition of the medium, by comparing its temperature with that of the same medium in the same environment as this device. If there is no corrosion in other areas, then it’s necessary to conduct analytical tests to determine the issue with this 316L material.

It is necessary to check the condition of the medium, by comparing its temperature with that of the same medium in the same environment as this device. If there is no corrosion in other areas, then it’s necessary to conduct analytical tests to determine the issue with this 316L material.

This post was last edited by nj1952 on 2017-7-4 at 15:01. Judging from the first photo: (1) Corrosion progresses from the outside inward； (2) In this pipe section, under the same operating conditions, the erosion suffered by the pipe is more severe than that of the flange ； (3) There are spiral-shaped deep corrosion marks on the outer surface of the pipe ； (4) The corroded pipes and flanges also exhibit a significantly different appearance in color; the pipes have completely lost the inherent color of 316 austenitic stainless steel, taking on the color of carbon steel after corrosion ； (5) The pipes and flanges suffer from uniform corrosion; compared to each other, the corrosion rate of the pipes is higher ； (6) The welds at the pipe-flange connection are eroded; corrosion is concentrated at the weld fusion line on the side of the pipe at the welding joint, and the pipe wall has been corroded through, showing clear signs of coulombic corrosion ； (7) The threads at the pipe end of the 3rd photo are corroded. Please have the original poster conduct further investigation: (1) The medium, components, and temperature of the pipeline transport ； (2) Are both the pipes and flanges made of 316 stainless steel? (Use a magnet to verify first, and then take samples to analyze their material composition.) (3) Are the third and first photos showing the same pipe section? (4) Is there any external anti-corrosion coating on the outside of the pipes (such as fiberglass wrapping)? Investigate the causes of the spiral corrosion marks on the outside of the pipe? Is the outside of the damaged pipe section in a humid and corrosive environment? (5) Is the corrosion concentrated on the outside of the pipe? What is the form of corrosion on its inner side? (6) What are the harmful substances in the atmosphere at the pipeline operation site? (7) Apart from this pipe section, are there any pipes in the plant that are subject to erosion under the same operating conditions? What are their respective patterns and degrees of erosion? (8) From a plan view of the device, is this pipe section an isolated incident? Does the eroded area have a certain orientation? Could it be affected by nearby devices?

Does higher temperature lead to more severe corrosion?

Yes, the higher the temperature, the worse it is; the higher the concentration, the worse it is.