Stainless Steel 317L (UNS S31703)

Alloy 317L is a molybdenum containing, low carbon austenitic stainless steel with increased additions of chromium, nickel, and molybdenum for better corrosion resistance and increased resistance to chemical attack for sulfurous, acetic, formic, citric, and tartaric acids. Due to its low carbon content, 317L also provides resistance to sensitization when welded and higher creep, stress to rupture, and tensile strength at elevated temperatures. It is non-magnetic in the annealed condition but may become slightly magnetic after welding.

Applications

Alloy 317L is commonly used to handle sulfur, pulp liquor, acid dyestuffs, acetylating and nitrating mixtures, bleaching solutions, severe coal and oil, and many chemical compounds. Some other applications that use alloy 317L include:

• Paper and pulp handling equipment
• Chemical and petrochemical processing equipment
• Condensers in fossil and nuclear fueled power generation stations
• Food processing equipment
• Textile equipment

Standards – Alloy 317L

ASTM/ASME: UNS N08020

EURONORM: FeMi35Cr20Cu4Mo2

DIN:  2.4660

• Resistance

Corrosion Resistance

• Demonstrates superior corrosion resistance in difficult environments including a wide range of chemicals, especially in acidic chloride environments
• Excellent resistance in applications where contamination is desired to be kept to a minimum
• Low carbon content allows 317L to be highly resistant to intergranular corrosion
• Combats the tendency to pit when in contact with phosphorus acids, chlorides, bromides, and iodides

Heat Resistance

• All chromium-nickel-molybdenum steels all have excellent resistance to oxidation
• Demonstrates a low rate of scaling in ordinary atmospheres at temperatures up to 1600-1650°F (871-899°C).
• Processing

Welding Characteristics

• All common fusion and resistance methods, with the exception of oxyacetylene welding, have proven successful
• AWS E317L/ER317L filler metal or austenitic, low carbon filler metals with molybdenum content higher than that of Type 317L, or a nickel-base filler metal with sufficient chromium and molybdenum content to exceed the corrosion resistance of Type 317L should be used to weld Type 317L steel

Machinability

• Low speeds and constant feeds will minimize this alloy’s tendency to work harden.
• Tougher than 304 stainless with a long stringy chip, the use of chip breakers is recommended

Chemical Properties:

%	Cr	Ni	C	Si	Mn	P	S	Mo	Fe
317L	min: 18.0 max:20.0	min: 11.0 max: 15.0	0.035 max	0.75 max	2.0 max	0.04 max	0.03 max	min: 3 max: 4	balance

Mechanical Properties:

Grade	Tensile Strength ksi (min.)	Yield Strength 0.2% Offset ksi (min.)	Elongation - % in 50 mm (min.)	Hardness (Brinell) MAX	Hardness (Rockwell B) MAX
317L	75	30	40	217	95

Physical Properties:

Denstiy lbm/in3	Coefficient of Thermal Expansion (min/in)-°F			Electrical Resistivity mW-in	Thermal Conductivity BTU/hr-ft-°F	Specific Heat BTU/lbm -°F
at 68 °F	at 77 – 212°F	at 77 – 932°F	at 77 – 1832°F		at 68 – 1832°F	at 32 – 212°F
0.29	9.2	10.1	10.8	31.1	14.6	0.11