317L is a molybdenum bearing austenitic chromium nickel steel similar to type 316, except the alloy content in 317L is somewhat higher.
Stainless 317 L has a high tensile and creep strength at elevated temperatures. Due to its excellent corrosion resistance it has been used in handling many of the chemicals used by the chemical process industries.
It has a supperior corrosion resistance in special applications where it is desired to reduce contamination to a minimum. 317L was developed primarily to resist more effectively the attack of sulfurous acid compounds. Howerver, its proven ability to combat corrosion has widened its use considerably and is now being used for many other industrial applications.
The low carbon content of 317L provides immunity to intergranular corrosion in applications where heavy cross sections cannot be annealed after welding or where low temperature stress relieving treatments are desired.
317L (00Cr19Ni13Mo3, SUS317L) alloy is based on molybdenum and austenitic stainless steel. It is more resistant to chemical corrosion than normal chrome-nickel austenitic stainless steel, such as 304 alloys. In addition, compared with conventional stainless steel, 317L alloys have higher ductility, anti-stress corrosion, compressive strength and high temperature resistance. It is a low carbon grade or L rating, which has the ability to resist sensitization during welding and heat treatment.
Grade | 317 | 317L |
---|---|---|
UNS Designation | S31700 | S31703 |
Carbon (C) Max. | 0.08 | 0.035* |
Manganese (Mn) Max. | 2.00 | 2.00 |
Phosphorous (P) Max. | 0.040 | 0.04 |
Sulphur (S) Max. | 0.03 | 0.03 |
Silicon (Si) Max. | 1.00 | 1.00 |
Chromium (Cr) | 18.0–20.0 | 18.0–20.0 |
Nickel (Ni) | 11.0–14.0 | 11.0–15.0 |
Molybdenum (Mo) | 3.0–4.0 | 3.0–4.0 |
Nitrogen (N) | — | — |
Iron (Fe) | Bal. | Bal. |
Other Elements | — | — |
Material | Ultimate Tensile Strength (Mpa) | 0.2 % Yield Strength (Mpa) |
% Elongation in 2" | Rockwell B Hardness |
Alloy 317 | 515 | 205 | 35 | 95 |
Alloy 317L | 515 | 205 | 40 | 95 |
Minimum Mechanical Properties by ASTM A240 and ASME SA 240 |
With hundreds of different types of steel alloys on the market, it can be tough to find the perfect metal for your application. In many buying processes, the first consideration is the cost of the metal rather than the performance of the metal—which can be a serious mistake.
There are some cases where paying extra for a different, higher-performing alloy is necessary.
What Makes Grade 317 SS Different from 304 & 316 SS?
Grade 304, 316, and 317 stainless steel are all considered austenitic stainless steel alloys. These alloys all share some similar properties, such as high strength, corrosion resistance, and high concentrations of chromium and nickel.
What separates 316 and 317 SS from 304 SS is that these higher-numbered alloys have added molybdenum in their formulation—grade 316 has about 2-3% molybdenum, and grade 317 has more than 3% molybdenum.
This added molybdenum greatly improves the steel’s resistance to pitting from chlorides, which is why grade 316 SS is often used in the chemical processing and marine industries.
However, this added molybdenum content also influences the cost of these two alloys. Grade 317 SS is generally more expensive than grade 316 SS. 316 SS, in turn, is more expensive than grade 304 SS. The exact extra cost varies based on the market at the time.
When is 317 SS Worth the Extra Cost Over 316 SS?
For most strongly corrosive applications, grade 316 should be more than enough to resist frequent exposure.
However, 317 does achieve better resistance to some specific corrosives than 304 or 316. As noted by an ATI Metals publication, in a boiling test solution of 1% hydrochloric acid, the corrosion rate of 317 SS was 54.2 mils/year, while 316 SS corroded at a rate of 226 mils/year. 317 SS also significantly outperforms 316 SS in sulfuric acid and sodium hydroxide tests.
So, if your processes involve the use of very diluted (less than 3-4%) hydrochloric acid, mild concentration (10%) sulfuric acid, or sodium hydroxide (aka caustic soda), then grade 317 stainless steel might be worth the extra cost over 316 or 304 SS.
It’s important to note that hydrochloric acid in any concentration above 5% will quickly erode any austenitic stainless steel alloy with ease.
Also, in the previously-cited chemical corrosion tests, 317 performed worse against some corrosives than 316, such as phosphoric acid (0.72 mils/year vs 0.2 mils/year) and acetic acid (0.48 mils/year vs 0.12 mils/year).
Also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.
304 Stainless is a low carbon (0.08% max) version of basic 18-8 also known as 302.
Type 316 is more resistant to atmospheric and other mild environments than Type 304.
310S Stainless Steel has excellent resistance to oxidation under constant temperatures to 2000°F.
317L is a molybdenum bearing austenitic chromium nickel steel similar to type 316, except the alloy content in 317L is somewhat higher.
Type 321 is basic type 304 modified by adding titanium in an amount at least 5 times the carbon plus nitrogen contents.
Type 410 is a martensitic stainless steel which is magnetic, resists corrosion in mild environents and has fairly good ductility.
2205双(不成功)S31803母材, or Avesta Sheffield 2205 is a ferritic-austenitic stainless steel.
Duplex 2507 (UNS S32750) is a super duplex stainless steel with 25% chromium, 4% molybdenum..
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ASTM A269 / A269M Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASME SA 249 Standard Specification for Welded Austenitic Steel Boiler,
Superheater, Heat-Exchanger, and Condenser Tubes.
904L stainless steel consists of chromium, nickel, molybdenum and copper contents, these elements give type 904L stainless steel excellent properties
Stainless steel is one of the more standardized materials in the building and engineering industries.
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