What is 317L Stainless Steel UNS S31703?

317L Stainless Steel Overview

Stainless Steel 317L is a molybdenum bearing, low carbon content “L” grade austenitic stainless steel that provides improved corrosion resistance over 304L and 316L stainless steels. The low carbon provides resistance to sensitization during welding and other thermal processes.

Stainless Steel 317L is non-magnetic in the annealed condition but may become slightly magnetic as a result of welding.

Corrosion Resistance

317L Stainless Steel has excellent corrosion resistance in a wide range of chemicals, especially in acidic chloride environments such as those encountered in pulp and paper mills. Increased levels of chromium, nickel and molybdenum compared to 316L stainless steel improve resistance to chloride pitting and general corrosion. Resistance increases with molybdenum alloy content.317L Stainless Steel is resistant to sulfuric acid concentrations up to 5 percent at temperatures as high as 120°F (49°C). At temperatures under 100°F (38°C) this alloy has excellent resistance to solutions of higher concentration. However, service tests are recommended to account for the affects of specific operating conditions that may affect corrosion behavior. In processes where condensation of sulfur-bearing gases occurs, 317L Stainless Steel is much more resistant to attack at the point of condensation than conventional alloy 316. The acid concentration has a marked influence on the rate of attack in such environments and should be carefully determined by service tests.

Chemical Composition, %

Ni

Cr

Mo

Mn

Si

11.0 – 15.0

18.0 – 20.0

3.0 – 4.0

2.0 Max

.75 Max

C

N

S

P

Fe

0.03 Max

0.1 Max

0.03 Max

0.045 Max

Balance

What are the characteristics of 317L Stainless Steel?

1. Improved general and localized corrosion to 316L stainless steel

2. Good formability

3. Good weldability

In what applications is 317L Stainless Steel used?

1. Flue-gas desulfurization systems

2. Stainless Steel Flanges
   

3. Chemical process vessels

4. Stainless Steel Pipe Fittings
   

5. Petrochemical

6. Pulp and Paper

7. Condensers in power generation

8. Stainless Steel Pipes

9. Stainless Steel Tubes
   

Mechanical Properties Minimum Specified Properties, ASTM A240

Ultimate Tensile Strength, ksi Minimum

.2% Yield Strength, ksi MinimumElongation Percent

Hardness Max.

75

30

35

217 Brinell

Welding 317L Stainless Steel

317L Stainless Steel is readily welded by a full range of conventional welding procedures (except oxyacetylene). AWS E317L/ER317L filler metal or austenitic, low carbon filler metals with molybdenum content higher than that of 317L, or a nickel-base filler metal with sufficient chromium and molybdenum content to exceed the corrosion resistance of 317L should be used to weld 317L steel.

Forms of 317L Stainless Steel Available at wilsonpipeline

1. Stainless Steel Sheets

2. Stainless Steel Plates

3. Stainless Steel Bars

4. Stainless Steel Pipes & Stainless Steel Tubes (welded & seamless)

5. Stainless Steel Pipe Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)

6. Stainless Steel Welding Wire and Stainless Steel Welding Electrode

Source: wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)