SX 316 / 316L Technical Data Summary
SX 316 is an improved version of SX 304, with the addition of molybdenum and a slightly higher nickel content. The resultant composition of SX 316 gives the steel much increased corrosion resistance in many aggressive environments. The molybdenum makes the steel more resistant to pitting and crevice corrosion in chloride-contaminated media, sea water and acetic acid vapours. The lower rate of general corrosion in mildly corrosive environments gives the steel good atmospheric corrosion resistance in polluted marine atmospheres. SX 316 offers higher strength and better creep resistance at higher temperatures than SX 304. SX 316 also possesses excellent mechanical and corrosion properties at sub-zero temperatures. When there is a danger of corrosion in the heat-affected zones of weldments, the low-carbon variety SX 316L should be used. SX 316 Ti, the titanium-stabilised version, is used for its resistance to sensitization during o o prolonged exposure in the 550 C-800 C temperature range. Typical Applications Because of its superior corrosion and oxidation resistance, good mechanical properties and fabricability, SX 316 has applications in many sectors of industry. Some of these include: Tanks and storage vessels for corrosive liquids. Specialised process equipment in the chemical, food, paper, mining, pharmaceutical and petroleum industries. Architectural applications in highly corrosive environments. Chemical Composition (ASTM A 240)
C SX316 SX316L SX316Ti 0.08 max 0.03 max 0.08 max
Mn 2.0 max
P 0.045 max
S 0.030 max
Si 1.0 max
Cr 16.0 to 18.0
Ni 10.0 to 14.0
Mo 2.00 to 3.00
Ti 0.5 max 5X%C
Typical properties in the annealed condition The properties quoted in this publication are typical of mill products and unless indicated must not be regarded as guaranteed minimum values for specification purposes. 1. Mechanical properties at room temperature SX316 Typical Tensile Strength, MPa Proof Stress (0.2 % offset), MPa Elongation (Percent in L = 5.65 So) Hardness (Brinell) Erichsen Cup Test Value mm Endurance (fatigue) limit, MPa 580 310 55 165 8 - 10 260 Minimum 515 205 40 570 300 60 165 10 - 11 260 SX316L Typical Minimum 485 170 40 600 320 50 165 260 SX316Ti Typical Minimum 515 205 40 -
2. Properties at elevated temperatures The values given refer to SX 316 and SX 316 Ti only as strength values for SX 316L fall rapidly above o 425 C. Short Time Elevated Temperature Tensile Strength Temperature, C Strength, MPa Creep data Stress for a creep rate of 1% in 10 000 h Temperature, C Stress, MPa
o
600 460
700 320
800 190
900 120
1000 70
550 160
600 120
650 90
700 60
800 20
Recommended Maximum Service Temperature (Oxidising conditions) Continuous Service 925 C o Intermittent Service 870 C 3. Properties at Sub-Zero Temperatures ( SX 316 ) Temperature Proof Strength (0.2% Offset) Tensile Strength Impact Strength (Charpy V-Notch) 4. Corrosion Resistance 4.1 Aqueous For specific conditions, consult VRN technical staff. As a rough guide, the following examples are given for pure acid-water mixtures. Temperature C Concentration, (-% by mass) Sulphuric Acid Nitric Acid Phosphoric Acid Formic Acid 012210 000001 000012 000110
o o
o
-78 400 820 180
-161 460 1150 165
-196 580 1300 155
MPa MPa J
20 10 20 40 60 80 100 222222 000012 000012 001110
80 10 20 40 60 80 100
Key: 0 = resistant - corrosion rate less than 100 m/year 1 = partly resistant - corrosion rate 100 m to 1000 m/year 2 = non resistant - corrosion rate more than 1000 m/year
4.2 Atmospheric The performance of SX 316 compared with other metals in various environments is shown in the following table. Corrosion rate is based on a 5 year exposure. Corrosion Rate (m/year) SX 316 0.0025 0.0076 0.0051 0.025 0.432 0.686 Aluminium-3S 5.8 34.0 46.2 Mild Steel
Environment Rural Marine Marine-Industrial
Note: For corrosion resistance of SX 316 relative to other types, see the section in Comparative Data. 4.3 Thermal Processing 4.3.1 Annealing. Heat from 1 010 C to 1 120 C and cool rapidly in air or water. The best corrosion o resistance is obtained when the final annealing temperature is above 1 070 C. 4.3.2 Stress relieving. Heat from 200 - 400 C and air cool. 4.3.3 Hot working o Initial forging and pressing: 1150 - 1200 C o Finishing temperature: above 900 C For upsetting operations, forgings o should be finished between: 930 and 980 C All hot working operations should be followed by annealing. Note: Soaking times to ensure uniformity of temperature are up to 12 times that required for the same thickness of mild steel. Cold Working SX 316 / 316L, being extremely tough and ductile, can be readily fabricated by cold working. Typical operations include bending, forming, deep drawing and upsetting
o o o
