Use and Care Manual

CVGRailings SPIGOT

CORROSION DATA

The United States and Canada are known to experience salt-laden mist originating from the oceans. The rainwater in

these regions also has chloride concentrations, and people use deicing salts in the mountainous or northern regions

within the U.S. All these scenarios lead to surroundings that are harsh to steel elements. As such, there’s signiﬁcant

application corrosion experienced in these regions.

The best way to minimize the effects of such harsh conditions and limit

corrosion is by using CVGRailings 316 Stainless Steel Spigots.

How Stainless Steel Beats Corrosion

You are already familiar with the effect of Chromium in reducing corrosion in stainless steel offshore applications. The

thin passive layer that covers the surface is usually tenacious. This means that even if you remove it by machining or

scratching, it will still form again. The extra nickel in 304 helps by broadening the passivity range. Grade 316 stands

out as the most robust since it contains at least 2% of molybdenum, a further addition that magniﬁes the passivity

range. Although molybdenum is found in some other grades of stainless steel, it is the relatively high concentration

present in 316 that helps to prevent the saltwater causing pitting or crevice corrosion.

Stainless steel should not rust if it has been well maintained. However, it is still likely to corrode when exposed to

several conditions. The process will be different from the rusting experienced by carbon steel. The most common

form of corrosion displayed by stainless steel is pitting, which occurs when the surrounding conditions overwhelm

the passive ﬁlm. The process is evident in small, dark-brown pits spread on the metal surface. However, it doesn’t

interfere with the steel’s mechanical properties.

Stainless steel also experiences crevice corrosion resulting from deposits that create crevices on metal surfaces.

It’s almost similar to pitting but covers a larger surface area. While it may not affect the steel’s mechanical processes,

crevices are not attractive. You can minimize this type of seawater corrosion by creating designs without sharp

corners and covering areas prone to cracking or pitting.

Causes of Corrosion on Stainless Steel in Marine Environments

No stainless steel is completely resistant to corrosion and the effectiveness varies

with various factors including:

• Grade of stainless steel used

• Service temperature

• The concentration of salt in the seawater

• Water ﬂow rates & oxygen levels of the water

• Amount of time in contact with saltwater

• Cleaning and maintenance frequency

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C HERCULES GLASS by ClearView CVGRailings SPIGOT CORROSION DATA GLASS RAILINGS The United States and Canada are known to experience salt-laden mist originating from the oceans. The rainwater in these regions also has chloride concentrations, and people use deicing salts in the mountainous or northern regions within the U.S. All these scenarios lead to surroundings that are harsh to steel elements. As such, there’s significant application corrosion experienced in these regions.
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Corrosion can occur in stages and increased chromium content in stainless steel can slow the process of corrosion down. The chromium on the surface of this steel creates a type of coating that protects the material from corrosion, when it is exposed to oxygen. This coating is what may appear as “rust” but is really working to slow corrosion on the material.