Wet and humid environments containing chloride ions can cause pitting corrosion and crevice corrosion of austenitic stainless steel components. Components under an applied or residual stress can deteriorate further by stress corrosion cracking in these conditions.
Can chlorine damage stainless steel?
Chlorine is very aggressive to stainless steels. Chlorine frequently causes corrosion problems. Chlorine attack can occur with bleach laden washdown water if pools form in drains which are usually empty.
What is the corrosion rate of stainless steel?
Type 316 stainless steel reaches a maximum critical corrosion rate of ≈ 18 mm/year in de-aerated 50 wt% NaOH solution at 90 °C at the peak of the active state, however the corrosion rate in the same environment at open circuit potential reaches a maximum of ≈ 0.5 mm/year.
Will chlorine corrode 304 stainless steel?
708), 304 stainless steel is resistant to localized corrosion by chlorinated fresh water up to 2 ppm chlorine.
Is chlorine corrosive to steel?
In contrast, wet chlorine is extremely corrosive to steel and many nickel alloys, and requires Alloy C-276 or titanium. Carbon steel resists dry chlorine and traces of moisture merely leave a film of ferric chloride.
Why does chlorine corrode stainless steel?
Chlorine affects stainless steel because it breaks down what is known as the ‘passive film’ on the surface of stainless steel. And once this happens, the stainless steel is vulnerable to corrosion and further pitting and damage.
Does chloride cause corrosion?
Low levels of chloride tend to cause general corrosion while high levels of chloride likely induce localized corrosion.
What are the grades of stainless steel?
The two most common stainless steel grades are 304 and 316. The key difference is the addition of molybdenum, an alloy which drastically enhances corrosion resistance, especially for more saline or chloride-exposed environments. 316 stainless steel contains molybdenum. 304 stainless steel does not.
Does 316 stainless steel corrode?
1. Corrosion Resistant Properties. Due to the addition of molybdenum, grade 316 stainless steel is more corrosion resistant than similar alloys, such as 304 stainless steel.
How much chlorine does it take to corrode stainless steel?
Cl2 (chlorine) is a very potent oxidizer (reason it kills bacteria) and therefore high levels of Chlorine may accelerate chloride corrosion of stainless steels. 304 and 304L, 321 SS may be used for “water applications” with up to 2 ppm chlorine, while 316 and 316L alloys may “take” up to 4 ppm.
What is the chloride content of 18-8 stainless steel?
Note: To print, please click here . The 304 and 304L (18-8 stainless steel alloys) have been utilized very successfully in fresh waters containing low levels of chloride ion of up to 100 ppm. This level of chloride is considered to be the limit for the 18-8 alloys, particularly if crevices are present.
Are stainless steels resistant to corrosion in highly concentrated sodium chloride?
This paper aims to explore the corrosion resistance of some stainless steels in highly concentrated sodium chloride solutions. The resistance to localized corrosion of stainless steels in 20,000,100,000 and 200,000 ppm Cl-sodium chloride solutions was investigated at 90°C.
What is the critical chloride to hydroxide ratio for pitting corrosion?
Evidence from the literature and from tests carried out for Nirex under the NSARP indicate that. the critical chloride to hydroxide ratio for pitting corrosion of stainless steel 316L in a. cementitious environment, C Cl/OH. , has a value of at least 14 at temperatures up to 70 °C.
