UNS S21800 Urea Class Stainless Steel

UNS S21800 stainless steel offers corrosion and abrasion resistance at a much lower cost than cobalt and nickel alloys. Its overall corrosion resistance is superior to Type 304 in most media. In UNS S21800, the resistance to chloride pitting is better than Type 316. The yield strength at room temperature is almost twice that of 304 and 316. UNS S21800 has excellent high temperature oxidation resistance and low temperature impact resistance.

MATERIAL DESCRIPTION FOR UNS S21800 / ALLOY 218 / NITRONIC® 60

NITRONIC® 60 is silicon/manganese alloyed austenitic stainless steel with double yield strength of AISI 304 material. The increased silicon and manganese level inhibit wear, galling and fretting and makes the alloy fit for temperatures up to 1000°C. General corrosion resistance is between AISI 304 and 316. It offers better chloride pitting resistance, stress corrosion cracking resistance and crevice corrosion resistance than AISI 316L in laboratory conditions.

Standard Specification of UNS S21800 / Nitronic 60 Alloy Stainless Steel

Applications

• Automotive valves - can withstand gas temperatures of upto 1500°F for a minimum of 50,000 miles.
• Fastener galling - capable of frequent assembly and disassembly, allowing more use of the fastener before the threads are torn up, also helps to eliminate corroded or frozen fasteners.
• Pins - Used in roller prosthetics & chains to ensure a better fit of parts (closer tolerance, non-lubricated) and longer lasting.
• Marine shafts - better corrosion than types 304 and 316, with double the yield strength.
• Pin and hanger expansion joints for bridges - better corrosion, galling-resistance, low temperature toughness, & high charpy values at sub-zero temps compared to the A36 and A588 carbon steels commonly used.

Chemical composition of UNS S21800 Alloy

Mechanical properties of UNS S21800 Alloy