Stabilised austenitic stainless steel, forging grade
ASTM A182 F316Ti Forgings UNS S31635 / W.Nr. 1.4571 / X6CrNiMoTi17-12-2 / AISI 316Ti
ASTM A182 F316Ti is the forging grade of titanium-stabilised 316 stainless steel. It carries the 316 chemistry of chromium 16.0 to 18.0 percent, nickel 10.0 to 14.0 percent and molybdenum 2.00 to 3.00 percent, with titanium added at a minimum of five times the carbon plus nitrogen content and 0.70 percent maximum. The titanium combines with carbon before chromium can, so the weld heat-affected zone does not sensitise, and the grade still certifies the standard 316 strength of 515 MPa tensile and 205 MPa yield minimum. Jiangyin Jiangnan Metal melts, forges, heat treats, machines and tests F316Ti at one works: rolled rings to OD 6000 mm, single pieces to 30 t, from a 10 kg minimum order.
Why the titanium addition is there
In a welded austenitic stainless steel, carbon can combine with chromium in the heat-affected zone and form carbides at the grain boundaries. The area next to the boundary is left short of chromium and loses corrosion resistance. Three grades answer this in different ways: 316L reduces the carbon, 316H accepts it for creep strength, and 316Ti fixes it with titanium.
Titanium content in 316Ti is typically around 0.5 percent. The titanium atoms stabilise the structure of 316 at temperatures over 800 C, which prevents carbide precipitation at the grain boundaries and protects the metal from corrosion. The steel can therefore be held at higher temperatures for longer periods than plain 316, while physical and mechanical properties stay close to the standard grade. For heavy welded sections, 316Ti may be used as an alternative to 316.
Full 316 strength
The certificate shows 515 MPa tensile and 205 MPa yield minimum, the same figures as standard 316, rather than the lower values certified for low-carbon supply.
Stable in warm service
A European mill data sheet states that grade 316Ti can be exposed in service for long periods at temperatures up to 500 C without loss of corrosion resistance.
Standard grade in Europe
1.4571 appears throughout DIN and EN piping classes, so replacement and extension parts on European-built plant are often specified in this grade to match the existing material.
Chemical composition
The American forging grade and the European grade are close but not identical in chromium, nickel, molybdenum and in the way the titanium requirement is written. State which standard governs the order so the heat can be aimed correctly.
| Element | ASTM A182 F316Ti (UNS S31635) | EN 10088-3, 1.4571, X6CrNiMoTi17-12-2 |
|---|---|---|
| Carbon (C) | 0.08 max | 0.08 max |
| Manganese (Mn) | 2.00 max | 2.00 max |
| Silicon (Si) | 1.00 max | 1.00 max |
| Phosphorus (P) | 0.045 max | 0.05 max |
| Sulphur (S) | 0.030 max | 0.03 max |
| Chromium (Cr) | 16.0 to 18.0 | 16.50 to 18.50 |
| Nickel (Ni) | 10.0 to 14.0 | 10.50 to 13.50 |
| Molybdenum (Mo) | 2.00 to 3.00 | 2.00 to 2.50 |
| Titanium (Ti) | 5 x (C+N) min, 0.70 max | 0.40 to 0.70 |
| Nitrogen (N) | 0.10 max | not specified |
| Iron (Fe) | Balance | Balance |
The carbon ceiling stays at 0.08 percent, the same as straight 316: the titanium addition is what makes a low-carbon variant unnecessary. In the ASTM text the titanium requirement is a formula rather than a fixed range, because the quantity needed depends on how much carbon and nitrogen it has to combine with, so a certificate showing titanium at five times carbon plus nitrogen is showing that the calculation has been met on that heat. Chemistry here is checked at the furnace by optical emission spectrometry to ASTM E415, with carbon and sulphur by infrared analysis to ASTM E1019, and confirmed by PMI on the finished part.
| System | Designation |
|---|---|
| ASTM / ASME | ASTM A182 F316Ti, ASME SA-182 F316Ti |
| UNS | S31635 |
| EN number | 1.4571 |
| EN name | X6CrNiMoTi17-12-2 |
| AISI and trade | AISI 316Ti, Alloy 316Ti |
| Related EN product standards | EN 10088-3 bar, EN 10222-5 forgings for pressure purposes, EN 10250-4 open-die forgings |
Mechanical and physical properties
| Property | ASTM A182 F316Ti | EN 10088-3, 1.4571 bar up to 160 mm dia. |
|---|---|---|
| Tensile strength, Rm | 515 MPa (75 ksi) min | 500 to 700 MPa |
| Yield / proof strength, Rp0.2 | 205 MPa (30 ksi) min | 200 MPa min |
| Elongation | 30% min, 2 in. or 4D | 40% min, A50 |
| Reduction of area | 40% min | not specified |
| Hardness | reported, or to order | 215 HB max |
| Property | Value |
|---|---|
| Density | 8.0 g/cm3 |
| Melting point | 1400 C |
| Modulus of elasticity | 193 GPa |
| Thermal expansion | 15.9 x 10-6 /K |
| Thermal conductivity | 16.3 W/m.K |
| Electrical resistivity | 0.74 x 10-6 ohm.m |
| Structure | Austenitic, tough down to cryogenic temperatures |
Heat treatment, forging, welding and machining
Heat treatment
316 type steels cannot be hardened by heat treatment. Solution treatment is carried out by rapid cooling after heating to 1010 to 1120 C; a European mill data sheet for 1.4571 gives 1030 to 1110 C with water or air cooling. Stress relieving is done at 200 to 400 C followed by air cooling. The plant runs 14 furnaces, including three high-temperature car-bottom furnaces and two 15 m well-type furnaces, so long F316Ti shafts can be quenched vertically. Every cycle is chart recorded against the heat number.
Hot working
All common hot working processes can be performed on 316 type steel. The ideal temperature range is 1149 to 1260 C, and working below 927 C should be avoided. Post-work annealing is recommended to ensure optimum corrosion resistance, which is why F316Ti leaves this works solution annealed unless the order states otherwise.
Welding
Fusion welding performance for 316 type steel is good both with and without fillers, and heavy welded sections may require post-weld annealing. Grade 316Ti is itself the recommended alternative to 316 for heavy section welds. Oxyacetylene welding is not suitable for this family of steels.
Machining
316 type steel has good machinability, but F316Ti is not a free-machining grade and is not suited to difficult high-speed machining. Keep cutting edges sharp, since dull edges cause excess work hardening. Cuts should be light but deep enough to prevent work hardening by riding on the surface. Use chip breakers and flood coolant.
Corrosion and heat resistance
Grade 316 has excellent corrosion resistance across a wide range of media and is usually regarded as marine grade, but it is not resistant to warm sea water. Warm chloride environments can cause pitting and crevice corrosion, and the grade is subject to stress corrosion cracking above around 60 C. For oxidation, 316 resists intermittent service to 870 C and continuous service to 925 C. Continuous use at 425 to 860 C is not recommended where corrosion resistance in water is required afterwards, and that band is where the stabilised grade is used in place of plain 316.
F316Ti product forms
Each item is forged from a single piece of steel melted on site. No welding, no casting, no purchased billet. The size limits below are the plant's working envelope.
Seamless rolled rings
Radial-axial rolled from a punched preform, rectangular or contoured section, OD 50 mm to 6000 mm. Bearing races, gear ring blanks, slewing and yaw rings.
Forged flanges
Weld neck, blind, slip-on, socket weld, lap joint, orifice, anchor, girth, swivel and long weld neck to ASME B16.5, B16.47 and API 6A.
Discs, tube sheets and covers
Solid forged discs and exchanger tube sheets to 5000 mm machined diameter, supplied proof-machined for volumetric inspection.
Shafts and spindles
Stepped, gear, pinion and eccentric shafts, rolls and rotors to 14,000 mm turned length, quenched vertically in the 15 m well furnaces.
Bars and blocks
Round, flat and square bars and blocks, used as the feedstock route for machined valve bodies, stems and tooling.
Sleeves, bushings and cylinders
Hollow forged cylinders and heavy-wall pipe sections bored from solid, to 1600 mm diameter by 10,000 mm on the CNC deep-hole drill.
Valve and wellhead parts
Bodies, bonnets, blocks, stems, seat rings, spools, nozzles and manifolds for ball, gate, globe, check and plug valves.
Forged rings
Upset and punched rings for sections outside the ring-mill envelope and where heavy reduction is preferred to rolling.
Custom open-die forgings
Gears, wheels, manifolds, crankshafts and one-off shapes to drawing, single pieces to 30 t.
Where F316Ti forgings are used
| Industry | Typical F316Ti forgings | Reason for the grade |
|---|---|---|
| Chemical and petrochemical | Vessel flanges, tube sheets, covers, nozzles, pump and valve parts | Welded assemblies in warm corrosive duty that cannot be solution annealed after fabrication |
| Pulp and paper | Digester and liquor tank components, paper machine parts, rolls | 316 was originally developed for use in paper mills |
| Refining and catalytic recovery | Flanges, forged pipe sections, tube sheets, recuperator parts | Resistance to carbide precipitation through long hot campaigns |
| Heat exchangers and pressure vessels | Tube sheets, discs, girth flanges, shell nozzles | Thick welded sections where 316Ti substitutes for 316 |
| Food, brewing and laboratory equipment | Bars, shafts, sleeves, process equipment components | Molybdenum-bearing corrosion resistance in acidic media. Electropolished work is normally 316L |
| Chemical transport and storage | Container fittings, manifolds, couplings | Intergranular resistance in the as-welded condition |
| Power and rotating equipment | Gear ring blanks, spindles, valve bodies, compressor parts | Standard 316 strength on a grade suited to welded construction |
F316Ti compared with related grades
All of the grades below are forged at this works, so the comparison does not depend on stock.
| Grade | Method | Specified when | Page |
|---|---|---|---|
| A182 F316Ti | Carbon fixed by titanium | Warm corrosive welded service, European 1.4571 specifications, matching existing plant, full 515 / 205 MPa required | This page |
| A182 F316L | Reduced carbon | Hygienic and electropolished work, wide availability, lower cost, at lower certified strength | F316L |
| A182 F321 and F347 | Stabilised with Ti or Nb, 18-8 without molybdenum | Elevated temperature service where chloride and acid attack is mild enough not to need molybdenum | F321 / F347 |
| A182 F51, F53, F55 | Duplex structure | Chloride stress corrosion cracking above 60 C, higher strength, seawater service | F51 / F53 / F55 |
| 904L, A182 F44, Alloy 20 | Higher nickel and molybdenum | Sulphuric and phosphoric acid duty and severe pitting environments beyond the range of 316 | 904L / F44 / Alloy 20 |
Testing, traceability and certification
The steel is melted here, so chemistry is verified at the furnace rather than taken from a supplier certificate, and traceability runs from the melt number through forging, heat treatment and machining to the shipped part.
| Item | Detail |
|---|---|
| Chemical analysis | Optical emission spectrometry to ASTM E415, carbon and sulphur by infrared to ASTM E1019, PMI on the finished piece |
| Mechanical testing | Tensile to ASTM A370 and ISO 6892 on 600 kN and 300 kN machines, Charpy V-notch with low-temperature bath to -60 C |
| Ultrasonic testing | ASTM A388, EN 10228-3, SEP 1921 acceptance classes as ordered |
| Magnetic particle and visual | ASTM E709, bore inspection by industrial endoscope |
| Grain size and metallography | ASTM E112 in the on-site metallographic laboratory |
| Intergranular corrosion | ASTM A262, and ASTM G28 where specified, placed with an accredited third-party laboratory and reported with the mill certificate |
| Certification | EN 10204 3.1 as standard, EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TUV or the customer's inspector on request |
| Class approvals | CCS, BV, DNV, LR, NK |
| Supporting records | Heat treatment charts, NDT reports, dimensional reports, PMI records |
Request a quotation
Sending these six items in the first email removes a round trip, and a price normally follows within two working days. Minimum order 10 kg with no minimum piece count, lead time 20 to 60 days.
| No. | Item | Example |
|---|---|---|
| 1 | Grade and governing standard | ASTM A182 F316Ti, or EN 1.4571 for a European project |
| 2 | Dimensions or drawing (PDF, DWG, DXF, STEP) | OD 1200 x ID 900 x H 260 mm |
| 3 | Quantity and expected repeat volume | 12 pcs, about 4 times per year |
| 4 | Delivery condition | Solution annealed, proof-machined for UT |
| 5 | Heat treatment and testing requirements | UT to EN 10228-3 Class 3, ASTM A262 Practice E |
| 6 | Certification and destination port | EN 10204 3.2 witnessed by DNV, Rotterdam |
Frequently asked questions
What is ASTM A182 F316Ti?
ASTM A182 F316Ti is the forging grade of titanium-stabilised 316 austenitic stainless steel, UNS S31635, known in Europe as W.Nr. 1.4571 or X6CrNiMoTi17-12-2 and commercially as AISI 316Ti. It has the chromium, nickel and molybdenum content of 316 plus titanium at a minimum of five times the carbon plus nitrogen content, to 0.70 percent maximum, so that carbon is combined as titanium carbide and chromium carbide does not precipitate at the grain boundaries.
What is the chemical composition of A182 F316Ti?
Per ASTM A182/A182M: carbon 0.08 max, manganese 2.00 max, silicon 1.00 max, phosphorus 0.045 max, sulphur 0.030 max, chromium 16.0 to 18.0, nickel 10.0 to 14.0, molybdenum 2.00 to 3.00, nitrogen 0.10 max, titanium five times carbon plus nitrogen minimum and 0.70 max. EN 10088-3 grade 1.4571 differs: chromium 16.50 to 18.50, nickel 10.50 to 13.50, molybdenum 2.00 to 2.50, titanium 0.40 to 0.70.
What are the mechanical properties of A182 F316Ti forgings?
Solution annealed to ASTM A182: tensile strength 515 MPa (75 ksi) minimum, yield strength 205 MPa (30 ksi) minimum, elongation 30 percent minimum, reduction of area 40 percent minimum. EN 10088-3 bar up to 160 mm diameter: proof stress 200 MPa minimum, tensile 500 to 700 MPa, elongation A50 40 percent minimum, hardness 215 HB maximum.
How is A182 F316Ti heat treated?
By solution annealing. 316 type steels cannot be hardened by heat treatment. Forgings are heated to 1010 to 1120 C and cooled rapidly in water or air; a European mill data sheet for 1.4571 gives 1030 to 1110 C with water or air cooling. Stress relieving is carried out at 200 to 400 C followed by air cooling.
What is the difference between 316Ti and 316L?
Both grades resist sensitisation, by different means. 316L uses a reduced carbon content; 316Ti uses a titanium addition and keeps the standard 316 strength of 515 MPa tensile and 205 MPa yield. Titanium carbides affect surface finish, so electropolished and hygienic work normally specifies 316L, while plant built to DIN and EN piping classes specifies 1.4571 and replacement parts have to match it.
Can F316Ti be used at elevated temperature?
Titanium stabilises the structure of 316 at temperatures over 800 C and prevents carbide precipitation at the grain boundaries, which is why the stabilised grade is used instead of plain 316 for elevated temperature and heavy welded work. One European mill data sheet states that grade 316Ti can be exposed in service for long periods at temperatures up to 500 C without loss of corrosion resistance. Creep-range allowable stresses are a separate question and belong to the higher carbon 316H.
Is F316Ti suitable for seawater service?
No. Grade 316 is regarded as marine grade but is not resistant to warm sea water. Warm chloride environments can cause pitting and crevice corrosion, and the grade is subject to stress corrosion cracking above around 60 C. The titanium addition does not change this. Duplex F51 or super duplex F53 and F55 are used for those services.
Which forged product forms are available in A182 F316Ti?
Seamless rolled rings and contoured rings from OD 50 mm to OD 6000 mm, forged rings, weld neck and blind flanges, discs, tube sheets and covers, shafts and spindles, round and flat bars, sleeves, bushings, nozzles, valve bodies, seat rings and stems, and bored hollow cylinders to 1600 mm diameter by 10,000 mm. Maximum single piece weight is 30 tonnes and maximum heat size is 60 tonnes.
What certification is supplied with F316Ti forgings?
EN 10204 3.1 mill test certificates as standard, and EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TUV or the customer's own inspector on request. Ultrasonic testing is carried out to ASTM A388 or EN 10228-3. Intergranular corrosion testing to ASTM A262 is placed with an accredited third-party laboratory when the order requires it. The works holds CCS, BV, DNV, LR and NK approvals.
Who manufactures ASTM A182 F316Ti open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997 with 460 staff. The works melts its own steel using EF, LF and VOD for stainless and duplex grades and VIM, VAR and ESR for clean and superalloy grades, then forges on 6300 t, 4000 t and 2000 t presses, rolls rings to OD 6000 mm, heat treats in 14 furnaces and machines and tests on site. Telephone +86 189 2135 9659, email sales@steelforgepieces.com.
What is the minimum order and lead time for F316Ti forgings?
Minimum order is 10 kg with no minimum piece count. Lead time is 20 to 60 days from order confirmation. Standard stainless grades such as F316Ti fall at the lower end because no remelting step is required. Witnessed inspection to EN 10204 3.2 and third-party corrosion testing should be stated at enquiry stage so they are included in the quoted date.
Jiangyin Jiangnan Metal Co., Ltd.
Integrated steel melting works, open-die forge and ring rolling mill, operating since 1997 and exporting to North America, Europe, the Middle East and Asia-Pacific.
Contact
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Business hours: Monday to Saturday, 08:00 to 17:30 China Standard Time (UTC+8)
Visiting the works
Jiangyin is between Shanghai and Nanjing on the south bank of the Yangtze. Wuxi Shuofang International Airport is 30 km away and Shanghai's airports are 160 km. The nearest export ports are Zhangjiagang and Shanghai. Customer audits, pre-shipment inspection and third-party witness testing are welcome. Please arrange visits by email in advance so that an English-speaking engineer is available.