304LN is used where an extremely low level of magnetic permeability is required. This derives from its high nitrogen content.

Approximate Composition – 18% Cr, 9% Ni, 0.15% N (Exact composition ranges vary between EN and ASTM standards).

This grade combines the following characteristics:

1、Moderate pitting and crevice corrosion resistance

2、Excellent impact toughness at sub-zero temperatures

3、Higher 0.2% PS than 304L

4、Non-magnetic. Very low ferrite level and very resistant to martensitic transformation. Relative magnetic permeability < 1.005

5、Good weldability. Care needed to avoid solidification cracking

304LN stainless steel was originally developed as a higher strength version of 304L using nitrogen. However, the increase in strength is only modest and duplex grades are now mostly used for this purpose. The grade is now used in specialised applications where a very low magnetic response is needed. In standard 304L, a typical level of relative magnetic permeability is around 1.05-1.1 due to small amounts of ferrite in the austenitic structure. A completely non-magnetic material would have a value of 1.0. 304LN can achieve a maximum value of around 1.005, which is the lowest practical level of any steel grade. It is also very resistant to transformation to the magnetic martensitic phase which can occur on forming or cooling to very low temperatures. Therefore, its main uses are in specialised equipment where magnetic “interference” needs to be avoided and/or for use in cryogenic equipment.

STANDARDS
INDUSTEEL TRADEMARKS		UNS	ASTM	EURONORMS EN	SUS
UR™ 304LN		S30453	304LN	1.4311 X2CrNiN18-10	SUS 304LN
CHEMICAL ANALYSIS (%WEIGHT)
C	Cr	Ni	Mo	N	Others
< 0,030	18,5	8,5	-	0,15

PROPERTIES
0,2 Y.S. - Rp 0,2min ASTM / EN		0,2 Y.S. - Rp 0,2(2)typical value		UTS - Rm min ASTM / EN		UTS - Rm(2)typical value		EI-A(1)%	PREN(4)	HOMOLOGATIONS
MPa	Ksi	MPa	Ksi	MPa	Ksi	MPa	Ksi			Last revised
270	39	335	49	550	80	630	91	45	21

APPLICATIONS
CHEMICAL INDUSTRIES			PROCESS INDUSTRIES			WATER TREATMENT			STORAGE & TRANSPORTATION
Nitric Acid	Sulfuric Acid	Polymer& otheracids	Fertilisers	Pulp& Paper	Hydrome-tallurgy	Seawater& desalination	Freshwater &Tanks	Waste Water	Chemical Tanks	Cryogenic Tanks	Renewable

POWER GENERATION				OIL & GAS			CONSTRUCTION
Nuclear	Pollution control	Hydroelectric	Renewable	Off & Onshore & production	Refining & Gas processing	Petrochemical	Architecture	Bridges

For more technical details :
(1) Indicative typical values
(2) Indicative typical values for thickness 20 mm at RT for transverse direction
(3) Hardening 496°C (925°F), 4h, air cooling
(4) PREN = Cr + 3.3 Mo + 16N
(5) PRENW = Cr + 3.3(Mo + 0.5W) + 16N
(6) HT: mechanical properties depend on heat treatment

PDF: http://www.industeel.info/wp-content/uploads/2016/01/DS-INOX-UR304LN-UR304Nv2.pdf