Hi All
I know a bit about corrosion but I am no expert. This one has been troubling me a bit.
While I was working in a mining site many years back, I had encounter a problem with galvanic corrosion in a filtration tank. It was repaired but I still trying to understand the corrosion process.
Tank was made up of 3 chambers.
Top chamber was made up of CS shell.
CS shell is welded to 304 Stainless Steel shell for the middle and bottom chambers.
Salty water from the bore fields enter via the middle chamber, passes through sand (medium) into the bottom chamber.
It overflow onto the top chamber where there is an outlet pipe.
Anode was not replaced as it should over the years, and what happen is that stainless steel section of the shell had crevices (internally) in many places. The carbon steel shell remains very good condition with hardly any metal loss.
I always thought the CS would be the sacrificial metal in this case. Any ideas?
I have attached a sketch of the filtration tank.
Thanks in advance.
I know a bit about corrosion but I am no expert. This one has been troubling me a bit.
While I was working in a mining site many years back, I had encounter a problem with galvanic corrosion in a filtration tank. It was repaired but I still trying to understand the corrosion process.
Tank was made up of 3 chambers.
Top chamber was made up of CS shell.
CS shell is welded to 304 Stainless Steel shell for the middle and bottom chambers.
Salty water from the bore fields enter via the middle chamber, passes through sand (medium) into the bottom chamber.
It overflow onto the top chamber where there is an outlet pipe.
Anode was not replaced as it should over the years, and what happen is that stainless steel section of the shell had crevices (internally) in many places. The carbon steel shell remains very good condition with hardly any metal loss.
I always thought the CS would be the sacrificial metal in this case. Any ideas?
I have attached a sketch of the filtration tank.
Thanks in advance.
