There are many types of corrosion that affect stainless steel metals. Household and industrial cleaners contain some of the worst chlorides! Chlorides – are found everywhere including in water, food and table salt.Be sure to remove deposits from food preparation and service. These can break down the passive layer leaving the stainless steel to rust. Hard water may leave spots and, when heated, leave deposits behind. Water – depending on where you live, your water can be hard or soft.Mechanical abrasion – steel pads, wire brushes and scrapers will scratch the steel surface.However, three things can break down this film: As long as the invisible film – or passive layer – remains intact, the metal remains stain-less and corrosion resistant. The chromium contained within stainless steel creates an invisible passive film covering the steel surface and shielding against corrosion. The addition of molybdenum (in marine grade stainless steel) only delays corrosion, it does not stop it. As such, regardless of whether you use 304 or 316L exposed stainless-steel cabinetry and appliances requires maintenance. It is also important to note that stainless steel is not stain proof it is stain less. Related – 304 VS 316 Stainless Steel: What’s the Difference? It is the molybdenum that enhances corrosion resistance in environments rich in salt air and chloride – giving 316L the moniker of “marine grade” stainless steel. The key difference between the 304 and the 316L is the addition of molybdenum in the 316L. Additional alloys typically include nickel, titanium, aluminum, copper, nitrogen, phosphorous, selenium and molybdenum. For a material to be considered stainless steel, at least 10.5% of the make-up must be chromium. Unlike the active metals mentioned above, stainless steel is referred to as passive because it contains other metals including chromium. Their numbers are determined by their alloy composition. The two grades of stainless steel most referenced in relation to outdoor environments are 304 and 316L, also known as marine-grade stainless steel. Metals such as iron and steel easily corrode – showing yellow or orange rust – within the natural environment and are called active metals. Here is a little background to help you understand why this myth has created confusion for the metals world.įirst, let’s take a look at the difference between active and passive metals. Myth Busted: Unfortunately, stainless steel is susceptible to rusting. Can stainless steel rust? This is a common question asked by many.

Will stainless steel tarnish