Nitronic
{{short description|Stainless steel alloy trade name}}
{{for|the nitronic acid functional group|Nitronate}}
{{Use mdy dates|date=August 2024}}
Nitronic is the trade name for a collection of nitrogen-strengthened stainless steel alloys. They are austenitic stainless steels.
History
Nitronic alloys were developed by Armco Steel. The first of these alloys, Nitronic 40, was introduced in 1961. Since 2022, the trademark has been owned by Cleveland-Cliffs Steel Corp., successor to AK Steel.{{cite web
| author =United States Patent and Trademark Office
| title =NITRONIC Serial# 73219917
| date =March 23, 2022
| pages =1
| url =https://tmsearch.uspto.gov/bin/gate.exe?f=doc&state=4809:hagi3e.2.1
| access-date = January 13, 2023
}}
Electralloy is the licensed producer in North America for a wide range of Nitronic products.{{cite web | url =http://www.electralloy.com/ | title =When your application is critical, when there is no room for error, your choice is Electralloy | date = 2017| website =Electralloy | quote =Electralloy is North America's exclusive licensed producer of all NITRONIC® bar, billet, coil rod, master alloy pigs and ingot products as well as NITRONIC® weld wire and weld consumables.}}
The Nitronic name is due to the addition of nitrogen to the alloy, which enhances the strength internally rather than being nitrided on the surface, as some steel are treated. The nitrogen is homogeneous throughout the material. Nitronic materials have about twice the yield strength of 304L and 316L.{{cite book
| author1 = C. G. Fountzoulas |author2=E. M. Klier |author3=J. E. Catalano
|editor1= Dan Casem |editor2=Leslie Lamberson |editor3=Jamie Kimberley
| title = Dynamic Behavior of Materials, Volume 1: Dynamic Characterization of Nitronic 30, 40 and 50 Series Stainless Steels
| date = 2016
| page = 22
|publisher=Springer | isbn=978-3319411323
| url = https://books.google.com/books?isbn=3319411322
| access-date = March 19, 2017
}}
Uses
Nitronic 30 is used to lighten transportation vehicles.{{cite web
| author =Bruce Emmons
| title = Ultralight Electric Bus
| date = June 27, 2016
| pages = 1
| url =https://contest.techbriefs.com/2016/entries/automotive-transportation/6924
| access-date = March 19, 2017
}}
Buses and railcars benefit from the high strength-to-weight ratio for weight savings. Nitronic 40 is used at cryogenic temperatures.{{cite book | last =Di Giovanni | first =Mario | title =Flat and Corrugated Diaphragm Design Handbook | publisher =CRC Press | date =1982 | pages =42 | url =https://books.google.com/books?id=_74dBADQSDIC&q=Nitronic+stainless+steel&pg=PA42 | isbn =9780824712815 }} and in the aerospace industry as hydraulic tubing.{{cite book
| author =Harold M. Cobb
| title =The History of Stainless Steel
| year =2010
| pages = 305
| publisher =ASM International
| isbn =9781615030118
| url =https://books.google.com/books?id=E30rCBeM8nkC&q=nitronic+40+hydraulic+tubing&pg=PA305
| access-date = March 19, 2017
}}
Nitronic 50 is used in marine environments, including boat shafting and solid rod rigging.{{cite magazine
| author =Dan Spurr
| title =Cruising World
| date = Jan–Apr 1982
| pages = 68
| url =https://books.google.com/books?id=ZSIKlK3ZmNIC&q=nitronic+solid+rod+rigging&pg=RA4-PA68| access-date = March 19, 2017
}}
Nitronic 60 and a similar alloy Gall-Tough have high resistance to galling, a form of wear caused by adhesion between sliding surfaces, and metal-to-metal wear.{{cite book | last = Davis | first =Joseph R. | title =Alloy Digest Sourcebook: Stainless Steels | publisher =ASM International | date = 2000| pages =3 | url =https://books.google.com/books?id=chuUynnDVJ8C&q=Nitronic+60&pg=PA3
Composition
Nitronic alloys have widely varying compositions, but all are predominantly iron, chromium, manganese and nitrogen.
| class="wikitable" style="text-align: center" |
| rowspan="2" | NITRONIC
! colspan="12" | Element (% by mass) |
|---|
| Fe
! Cr ! Ni ! Mo ! Nb ! Mn ! Si ! C ! S ! P ! V ! N |
| 30 UNS S20400
| author =AK Steel | title = Nitronic 30 Stainless Steel | url =http://www.aksteel.com/pdf/markets_products/stainless/austenitic/NITRONIC_30_Stainless_Steel_PDB_201512.pdf | access-date = March 19, 2017 }} | Bal | 15.0–17.0 | 1.5–3.0 | | | 7.0–9.0 | 1 max | 0.03 max | 0.03 max | 0.04 max | | 0.15–0.3 |
| 32 UNS S24100
| author =Electralloy | title = Nitronic 32 Stainless Steel | url =http://www.electralloy.com/images/pdf/Product_Sheets/Electralloy/Nitronic_32.pdf | access-date = March 19, 2017 }} | Bal | 16.5–19.0 | 0.5–2.5 | | | 11.–14.0 | 1 max | 0.15 max | | 0.045 max | | 0.2–0.45 |
| 33 UNS S24000
| author =Electralloy | title = Nitronic 33 Stainless Steel | url =http://www.electralloy.com/images/pdf/Product_Sheets/Electralloy/Nitronic_33.pdf | access-date = March 19, 2017 }} | Bal | 17.0–19.0 | 2.3–3.7 | | | 11.5–14.5 | 0.75 max | 0.08 max | 0.01 max | 0.06 max | | 0.–0.4 |
| 40 UNS S21900
| author =Electralloy | title = Nitronic 40 Stainless Steel | url =http://www.electralloy.com/images/pdf/Product_Sheets/Electralloy/Nitronic-40.pdf | access-date = March 19, 2017 }} | Bal | 19–21.5 | 5.5–7.5 | | | 8.0–10.0 | 1 max | 0.04 max | 0.01 max | 0.04 max | | 0.2–0.4 |
| 50 UNS S20910
| author =Electralloy | title = Nitronic 50 Stainless Steel | url =http://www.electralloy.com/images/pdf/Product_Sheets/Nitronic/Nitronic50HS_main.pdf | access-date = March 19, 2017 }} | Bal | 20.5–23.5 | 11.5–13.5 | 1.5–3.0 | 0.01–0.03 | 4.0–6.0 | 0.2–0.6 | 0.03 max | 0.01 max | 0.04 max | 0.1–0.03 | 0.2–0.4 |
| 60 UNS S21800
| author =Electralloy | title = Nitronic 60 Stainless Steel | url =http://www.electralloy.com/images/pdf/Product_Sheets/Nitronic/Nitronic60_main.pdf | access-date = March 19, 2017 }} | Bal | 16–17 | 8.0–8.5 | 0.75 max | 0.10 max | 7.5–8.5 | 3.7–4.2 | 0.06–0.08 | 0.03 max | 0.040 max | 0.2 max | 0.1–0.18 |