June 11, 2024
Posted by: Explore Middle East FZE

Difference between 316L and 317L Stainless Steel

  • In a variety of chemical conditions, 317L exhibits exceptional resistance to corrosion, particularly in acidic chloride situations like those found in pulp and paper mills. In comparison to 316L stainless steel, higher concentrations of chromium, nickel, and molybdenum enhance resistance against chloride pitting and general corrosion.
  • The Alloy used for bleaching solutions, harsh coal and oil, pulp liquor, Sulfur, acetylating and nitrating mixes, acid dye stuffs and numerous chemical compounds are all handled with 317L stainless steel. 316L is Utilized in many Industries and Applications For instance, professionals utilize it to create surgical instruments and medical implants in the chemical and pharmaceutical industries. This alloy can also be used to make equipment for the petroleum refining sector and textile tubing.
  • Difference between 316L SS and 317L SS is in chemical composition percentages. 317L has chromium content between 18-20% and 316L has 16-18% chromium.
  • Low carbon, corrosion-resistant austenitic chromium-nickel-molybdenum stainless steel is known as Alloy 317L (UNS S31703). The austenitic stainless steel alloy 316/316L (UNS S31600/ S31603) is composed of chromium, nickel, and molybdenum.
  • In general, grade 317L Stainless steel cost higher than grade 316L Stainless Steel. Alloy 317L is more costly because of longer lifespan, which is demonstrated by the fact that it lasts longer before collapsing in the same way as 316L SS. It justifies its higher cost.
  • 7.89 g/cm3 is the density of 317L stainless steel grade and 316L coming with density of 7.90g/cm3
  • At 20°C, the electrical resistivity of 317L is 85.1 microhm-cm, whereas that of 316L is 74 microhm-cm.
  • Austenitic stainless steel with chromium, nickel, and molybdenum content is WNR 1.4438 / AISI 317L. Greater resistance to corrosion than AISI 316L stainless steel WNR 1.4404, particularly in highly corrosive conditions containing halides and chlorides.

Check Suitable List of Acids and Complete Data Sheet of AISI 316L and 317L

316L and 317L Stainless Steel Data Sheet

SS 316L SS 317L
Alloy Group
  • Austenitic
  • Austenitic
PRE
Pitting corrosion resistance
  • 24
  • 28
CPT
Critical Pitting Temperature
  • 16 ± 0.7 °C
  • 33±3
Equivalent
  • UNS S31603
  • X2CrNiMo17-12-2
  • DIN 1.4404
  • British BS 316S11
  • Sweeden SS 2348
  • UNS S31703
  • X2CrNiMo19-14-4
  • DIN 1.4438
  • British BS 317S12
  • Sweeden SS 2367
Density
  • 8000 kg/m³
  • 8000 kg/m³
Electrical Resistivity
  • 740 nΩ.m
  • 790 nΩ.m
Yield Strength 25,000 psi 30,000 psi
Tensile Strength 485 MPa 515 MPa
Price per Kg in US$ US $1.40 Per Kg US $1.80 Per Kg
American Standard
  • ASTM A240 Type 316L
  • ASTM A312 TP 316L
  • ASTM A480 Grade 316L
  • ASTM A240 Type 317L
  • ASTM A312 TP 317L
  • ASTM A480 Grade 317L
Suitable Acids and Chemicals
  • Sulfuric Acid
  • Phosphoric Acid
  • Nitric Acid
  • Acetic Acid
  • Citric Acid
  • Formic Acid
  • Hydrochloric Acid
  • Sulfuric Acid
  • Phosphoric Acid
  • Nitric Acid
  • Acetic Acid
  • Citric Acid
  • Formic Acid
  • Hydrochloric Acid
Do not use with these Acids and Chemicals
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid (HF)
  • Chlorides
  • Sulfuric Acid
  • Bromine, Iodine, and Chlorine
  • Hydrochloric Acid (HCl)
  • Hydrofluoric Acid (HF)
  • Chlorides
  • Sulfuric Acid
  • Bromine, Iodine, and Chlorine
Best to use for
  • Chemical and Petrochemical Processing
  • Chemical and Plant Construction
  • Pharmaceutical & high purity
  • Gas Chromatography
  • Laboratories
  • Oxygen-Enriched Environments
  • Semiconductor fabrication
  • Textile Equipment
  • Food processing and equipment
  • Power Plant Condensers
  • Power Plant Desulphurization
  • Pulp Mill Bleach Systems
Filler Metal & welding of AISI 316L
  • AWS A 5.9: ER316L
  • AWS A 5.9: ER317L
Post Weld Heat Treatment Not Required Not Required
Features
  • Weld stabilized grade
  • Used for highly corrosive environments
  • Used for extremely corrosive environments
  • Suitable for acidic chloride environments
  • High value of chromium, nickel and molybdenum compared to SUS 316L
  • Widely used in pulp and paper mills

Chemical composition

AISI 316L

316l stainless steel chemical composition

AISI 317L

Chemical composition of 317l stainless steel

What does the L stand for in 316L?

What does the L stand for in 316L?

‘L’ stands for low; it means very low carbon content is in 316L stainless steel. Comparing the 316L type to the 316 version, it can tolerate higher temperatures and is also more resistant to weld degradation. For this reason, 316L is frequently used in building and marine applications.

AISI 317L

The primary attribute of stainless steel AISI 317L is the significant molybdenum addition to its chemical composition. This ensures a higher resistance to chemical attack in comparison to austenitic steels of type AISI 316L that are chromium-nickel-molybdenum.

317L stainless steel uses and applications

Stainless steel grade 317L is frequently used in the following applications: Carbon-based condensers. manufacturing of paper and pulp. nuclear power plants for electricity generating.

Excellent corrosion resistance to a broad variety of substances is possessed by alloy 317L. It is resistant to attack from phosphoric acid, sulfuric acid, and acidic chlorine. It is employed in applications including the processing of food and pharmaceuticals to handle heated organic and fatty acids.

Compared to 304L and 316L, stainless steel 317L (UNS S31703), an austenitic stainless steel with a low carbon content and molybdenum content, creates better corrosion resistance. The resistance to chemical assault of this alloy steel is significantly enhanced. Furthermore, compared to conventional stainless steels, Alloy 317L provides higher creep, stress to rupture, and tensile strength at higher temperatures.

There is various application used of 317L stainless steel such as:

Aerospace industry

Stainless steel 317L is resistant to consumption and prepared to endure the most severe weather conditions. Because aeroplanes operate in a variety of climates, altitudes, and precipitation conditions, this feature makes it ideal for aeroplanes. Furthermore, the material is extremely durable, which is a crucial characteristic when working in the air.

Healthcare

Restorative equipment is a well-known use and should be in excellent shape and prepared for efficient purification. This level of tidiness is provided to gadgets and other medical apparatuses by 317L steel.

Oil and Gas companies

317L Stainless steel is used in the gas and oil industry. For these uses, this alloy material is suitable. This element is used in the pipeline industry, submarine pipelines and under water equipment because 317L has the quality to stand up in the high pressure and under the earth surface. 317L is also used in the mechanical parts that are resistant to corrosion.

Food Industry

Excellent corrosion resistance to a broad variety of substances is possessed by alloy 317L. It is resistant to attack from phosphoric acid, sulfuric acid, and acidic chlorine. It is employed in applications including the processing of food and pharmaceuticals to handle heated organic and fatty acids.

Which is cheaper: 317L or 316L?

316L stainless steel is cheaper than 317L stainless steel because SS 317L resists galvanic corrosion between the heat exchanger’s plates and frame significantly better than SS 304L and SS 316, it is a useful material in the manufacturing of heat exchangers.

Due to less nickel content in 316L SS than 317L SS there is a big difference in the cost of both elements. Nickel is a high-cost element which increases the corrosion resistance and toughness in 317L stainless steel and raises the cost of production process.

SUS 316L vs 317L in Corrosive Environments

SS 317L elements have more corrosion resistance than 316L SS. 317L stainless steel is better to perform in high temperature environments and with aggressive chemicals. 317L SS has a heat resistance up to 950°C (1742°F) than 316L SS. It is ideal for nuclear power plants and chemical processing machinery.

The chromium percentage of 317L has 18-20% and 316L has 16-18% of chromium. Nickel elements are present 11-15% in 317L SS and 10-13% in 316L SS. The difference in chemical composition of both elements make it better to choose 317L SS for corrosive environments.

Impact on SS 316L after corrosion tests in the boiling solutions

Impact on AISI 317L after corrosion tests in the boiling solutions

Corrosion Rate in Mils per Year
Base material Welded Base material Welded
Acetic Acid 20% 0.12 0.12 0.48 0.36
Formic Acid 45% 23.4 20.9 18.3 24.2
Hydrochloric Acid 1% 0.96 63.6 54.2 51.4
Oxalic Acid 10% 48.2 44.5 44.9 43.1
Phosphoric Acid 20% 0.60 1.08 0.72 0.60
Sulfamic Acid 10% 124.2 119.3 94.2 97.9
Sulfuric Acid 10% 635.3 658.2 298.1 356.4
Sodium Bisulfate 10% 71.5 56.2 55.9 66.4
Sodium Hydroxide 50% 77.6 85.4 32.8 31.9