Nitronic 50 stainless steel - UNS S20910 - XM-19

Nitronic 50 stainless steel is an austenitic stainless steel renowned for its exceptional resistance to corrosion, wear, and galling.

The generic name for Nitronic 50 is XM-19 (sometimes written as XM19) and is sometimes referred to as UNS S20910 Nitronic 50. XM-19 is the designation of the generic alloy caption in ASTM A276 and ASTM A479, as well as UNS S20910 or DIN 1.3964.

NITRONIC 50 stainless steel is a cost-effective solution for areas requiring corrosion and strength resistance. It provides corrosion resistance that surpasses Types 316 and 316L and twice the yield strength of standard austenitic stainless steels. With superior mechanical properties at both high and low temperatures, NITRONIC 50 is an excellent choice that won't become magnetic even when cold worked.

Nitronic 50 Stainless Steel can be supplied annealed at 1950 F to 2050 F (1066 C to 1121 C). For most applications, the 1950 F (1066 C) condition should be selected, as it provides a higher level of mechanical properties along with excellent corrosion resistance. When as-welded material is to be used in strongly corrosive media, the 2050 F (1121 C) condition should be specified in order to minimize the possibility of intergranular attack.

Nitronic 50 Stainless Steel provides outstanding corrosion resistance - superior to Types 316, 316L, 317 and 317L in many media. For many applications the 1950 F (1066 C) annealed condition provides adequate corrosion resistance and a higher strength level. In very corrosive media or where material is to be used in the as-welded condition, the 2050 F (1121 C) annealed condition should be specified. High-Strength (HS) NITRONIC 50 bars are useful for applications such as shafting and bolting, but do not quite exhibit the corrosion resistance of the annealed conditions in all environments.

The resistance to intergranular attack is excellent even when sensitized at 1250 F (675 C) for one hour to simulate the heat-affected zone of heavy weldments. Material annealed at 1950 F (1066 C) has very good resistance to intergranular attack for most applications. However, when thick sections are used in the as-welded condition in certain strongly corrosive media, the 2050 F (1121 C) condition gives optimum corrosion resistance.

In common with most stainless steels, under certain conditions, Nitronic 50 Stainless Steel may stress-corrosion crack in hot chloride environments. When tested in boiling 420/0 MgCI2 solution, a very accelerated test, Nitronic 50 Stainless Steel is between types 304 and 316 stainless steels in resistance to cracking. There is little difference in susceptibility to cracking whether in the annealed, high-strength (HS), or cold-drawn conditions.

Both laboratory tests and field service experience have shown that Nitronic 50 stainless has excellent resistance to sulfide stress cracking in air conditions. Nitronic 50 in both the annealed and high-strength (hot rolled) conditions has been included in the 1996 revision of NACE Standard MR-01 -75'"Sulfide Stress Cracking Resistant Metallic Material for Oil Field Equipment,"at hardness levels up to RC 35 maximum. The resistance to cracking in laboratory tests in synthetic sour-well solution(5% NaCI + ½% acetic acid. saturated with H2S)

Nitronic 50 is annealed between 1950 deg F and 2050 deg F. For critical applications that need to withstand high corrosive environments, the higher end of the range should be used. The annealing process helps achieve the alloy’s high corrosion resistant properties.

 

Nitronic 50 is then cold worked if transforming into high strength. The increased mechanical properties make it appropriate for oil & gas completion components, downhole drilling tools, marine applications, boat & pump shafting, and valve stems. Due to its ability to work harden, machining Nitronic 50 requires slower speeds and higher power.

Nitronic 50 stainless steel can be worked both in cold and hot conditions. Understanding the differences between cold and hot working processes is essential for achieving the desired mechanical properties and microstructure in your components. Cold drawn Nitronic 50 is favored in applications where precise dimensions and enhanced mechanical characteristics are required.