Stainless Steel

Stainless steel is a type of steel alloy that combines iron with other elements, such as chromium, nickel, and molybdenum. It is known for and used for its ability to resist oxidation. There are hundreds, if not thousands, of grades of stainless steel. Some of the more common grades are:

• 304 Stainless - Very common alloy used in utensils and many household items. Generally, 304 stainless will contain 7-9% nickel, 18-20% chromium, and up to 2% manganese, and the balance of the material is iron.
• 316 Stainless - Also a common alloy, similar in use to 304 Stainless. 316 stainless contains 9-11% nickel, 15-17% chromium, up to 2% manganese, and up to 2% molybdenum.
• 400 Series Chrome Steel - Contains various grades of stainless steel (410, 430, etc.) that generally contain little to no nickel and varying amounts of chromium, upwards of 27%.
• 17-4 PH - Contains 4% nickel, 17% chromium, and 3-4% copper. This alloy is used in the aircraft industry.

Elements Generally Contained in Stainless Steel Alloys

• Nickel
• Chromium
• Iron
• Manganese (usually no higher than 2%)
• Carbon (usually no higher than 0.5%)
• Silicon (usually no higher than 1%)

There is usually a trace amount of phosphorus, sulfur, and boron found in stainless alloys due to contaminants in the scrap metal or additives used in the melting process.

Elements Found in Few Stainless Steel Alloys

• Cobalt
• Copper
• Vanadium
• Tungsten
• Molybdenum
• Zirconium
• Nitrogen (trace)
• Aluminum
• Titanium
• Niobium
• Tantalum
• Yttrium (usually found as an oxide, Y₂O₃)

Elements Usually Considered Contaminants

• Tin
• Lead
• Zinc
• Arsenic

See also

• Steel