1.4986 (X7CrNiMoBNb16-16) forgings: rings, flanges, bars, hollow sections, discs
Data sheet and forged product forms for EN 10269 grade 1.4986. Melted and forged at Jiangyin Jiangnan Metal Co., Ltd., a steel melting works and open-die forge in Jiangyin, Jiangsu Province, China.
Grade. 1.4986, chemical designation X7CrNiMoBNb16-16, is a boron and niobium alloyed austenitic heat resistant steel standardised in EN 10269, the European standard for steels and nickel alloys for fasteners with specified elevated and low temperature properties. Nominal chemistry is 16 % Cr, 16 % Ni and 2 % Mo with 0.05 to 0.10 % B and Nb+Ta from 10 x C up to 1.20 %. The superseded German designation under DIN 17240 was X8CrNiMoBNb16-16.
Supplied condition. +WW+P, warm worked and precipitation hardened. Up to 100 mm diameter: Rp0.2 min 500 MPa, Rm 650 to 850 MPa, A min 16 %, KV2 min 50 J at 20 C. EN 10269 tabulates strength to 650 C.
Product range. Seamless rolled rings to OD 6000 mm, single pieces to 30 t, minimum order 10 kg, lead time 20 to 60 days, EN 10204 3.1 certification as standard and 3.2 witnessed certification on request. Steel is melted in our own furnaces, so traceability starts at the melt number.
Price. Quoted per drawing. There is no list price for an open-die forging, because cost follows the finished weight, the input weight before machining, the forging route, the heat treatment, the testing scope and the certification level.
Designations and standards
| System | Designation | Scope |
|---|---|---|
| EN material number | 1.4986 | Numeric designation used in EN 10269, listed in EN 10088-1, list of stainless steels |
| EN material name | X7CrNiMoBNb16-16 | Chemical designation: 0.07 % C nominal, Cr Ni Mo B Nb alloyed, 16 % Cr and 16 % Ni |
| EN 10269 | X7CrNiMoBNb16-16, austenitic steels | Steels and nickel alloys for fasteners with specified elevated and low temperature properties; also applicable to finished fasteners |
| DIN 17240, 1976, withdrawn | X8CrNiMoBNb16-16 | Heat resisting and highly heat resisting materials for bolts and nuts; replaced by DIN EN 10269:1999 |
| German material sheets | WB 113/1 and WB 113/2, 2001 | Heat resistant austenitic rolled and forged steel X8 CrNiMoBNb 16 16, WN 1.4986 |
| AISI and UNS | No direct equivalent | See the note below |
Incorrect equivalents in circulation
Two claims about 1.4986 appear on supplier websites and do not hold against the standards. The first calls 1.4986 a martensitic stainless steel. EN 10269 lists it with the austenitic steels, EN 10088-1 classifies it as austenitic, and the 16 % nickel content holds the austenite stable. The second gives UNS N07718 as the equivalent. N07718 is a nickel base precipitation hardening alloy with a different base chemistry, and no AISI or UNS grade matches the 16 Cr, 16 Ni, 2 Mo, B, Nb combination. The grade is precipitation treated, which is the likely source of both errors, but the matrix stays austenitic. Where a project specification asks for a cross referenced US grade, have the requirement written against EN 10269 rather than an assumed equivalent.
Chemical composition
| C | Si | Mn | P | S | Cr | Ni | Mo | B | Nb+Ta | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.04 to 0.10 | 0.30 to 0.60 | max 1.00 (a) | max 0.045 | max 0.030 (b) | 15.5 to 17.5 | 15.5 to 17.5 | 1.60 to 2.00 | 0.05 to 0.10 | 10 x C to 1.20 | balance |
(a) Editions differ. The 1999 edition of EN 10269 gives Mn max 1.00 %, later published tables of the standard and
the withdrawn DIN 17240 give Mn max 1.50 %. Confirm which edition the specification invokes.
(b) Sulphur is max 0.030 % in the 1999 edition and max 0.015 % in later tables, with controlled sulphur of 0.015 to 0.030 %
recommended for machinability and 0.008 to 0.030 % for weldability, agreed at enquiry and order. No aluminium or vanadium limit
is specified for this grade.
Function of the alloying elements
Boron at 0.05 to 0.10 % is high for a stainless steel and is the defining feature of the grade. It segregates to grain boundaries and raises high temperature creep strength. Niobium, specified as Nb+Ta at a minimum of ten times the carbon content, fixes carbon as stable niobium carbide, which limits sensitisation and adds strength at temperature. Molybdenum at 1.6 to 2.0 % raises hot strength and resistance in aggressive media. The equal 16 % Cr and 16 % Ni balance gives a stable austenitic structure with a chromium oxide layer for oxidation resistance.
Mechanical properties at room temperature
| Property | Symbol | Requirement, d max 100 mm |
|---|---|---|
| 0.2 % proof strength | Rp0.2 | min 500 MPa, 72.5 ksi |
| Tensile strength | Rm | 650 to 850 MPa, 94 to 123 ksi |
| Elongation after fracture | A | min 16 % |
| Impact energy, ISO-V at 20 C | KV2 | min 50 J, 37 ft lb |
| Reduction in area, DIN 17240 | Z | min 40 % |
| Impact energy, DVM specimen, DIN 17240 | - | min 48 J |
The upper limit of the tensile strength range must not be exceeded. Under the withdrawn DIN 17240 rule, values slightly below the lower limit were permitted provided the minimum yield point was reached; apply the EN 10269 requirement unless the order states otherwise. For rectangular sections the diameter d is replaced by the thickness b.
Strength at elevated temperature
EN 10269 tabulates minimum short term strength for 1.4986 in the +WW+P condition to 650 C for diameters up to 100 mm. These are hot proof and tensile values, not creep rupture values.
| Temperature C | 50 | 100 | 150 | 200 | 250 | 300 | 350 | 400 | 450 | 500 | 550 | 600 | 650 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rp0.2 min | 489* | 470* | 451* | 432 | 412 | 393 | 372 | 353 | 334 | 314 | 284 | 255 | 206 |
| Rm min | 635 | 615 | 590 | 570 | 550 | 530 | 505 | 485 | 460 | 440 | 420 | 395 | 375 |
* Values obtained by linear interpolation in the standard.
Service temperature
DIN 17240 gave 650 C as the guidance value for the normal upper limit of temperature in continuous operation for bolts in this grade, and allowed up to 50 C higher for nuts. Supplier literature for the grade describes service to roughly 600 to 700 C depending on load and atmosphere. EN 10269 publishes short term proof and tensile values for 1.4986 rather than creep rupture curves, so any design that puts the grade into the creep range needs creep data agreed in writing at enquiry stage rather than the table above. For fastener use the standard covers service from cryogenic temperatures upward; one bolting supplier states a working range of minus 200 C to plus 700 C for EN 10269 fasteners in this grade.
Physical properties
| Property | Value | Source |
|---|---|---|
| Density | 7.9 g/cm3, 0.285 lb/in3 | Consistent across independent grade databases |
| Modulus of elasticity at 20 C | 196 GPa and 200 GPa | 196 per VIRGAMET, 200 per MakeItFrom; use 196 to 200 GPa |
| Specific heat capacity | 460 to 470 J/kg K | VIRGAMET, MakeItFrom |
| Thermal conductivity at 20 C | 15 W/m K | VIRGAMET, MakeItFrom |
| Coefficient of linear expansion | 16.6 x 10-6 1/K, 17 micrometre/m K | VIRGAMET, MakeItFrom |
| Brinell hardness, aged | 230 HB | MakeItFrom, indicative, not an EN requirement |
| PREN, calculated | 22 | MakeItFrom calculation; 1.4986 is a heat resisting grade, not a pitting resistant one |
Physical properties are not specified in EN 10269. The figures above come from independent grade databases and are for design guidance. Where a value is contractually important, ask for it to be measured on the actual heat and reported on the certificate.
Heat treatment, forging, machining, welding
Heat treatment
The solution annealed austenitic grades in EN 10269 take one treatment. 1.4986 takes two. The heat treatment guidance in the standard gives the condition for 1.4986 as +WW+P: warm working at 750 to 850 C followed by a precipitation treatment at 750 to 800 C. A 1.4986 part cannot be re-solution-annealed after machining without losing the mechanical values the standard requires, because the deformation history forms part of the property specification. Where a forging cannot follow the bar route exactly, agree the treatment and the test location with us before the order is placed so the certificate matches the drawing.
Forging and machining
German material sheets WB 113/1 and WB 113/2 cover 1.4986 in the rolled and forged condition, so open-die forging is a standard route for the grade. Like other boron and niobium bearing austenitic steels it work hardens, so machining calls for rigid setups, carbide tooling, generous coolant and controlled feeds rather than high surface speed. Heavy cold deformation without a subsequent treatment should be avoided. Forging reductions and temperatures are set per order at this works against the section size and the final property requirement.
Welding
For procedure qualification 1.4986 falls in group 8.1 of ISO/TR 15608, austenitic steels with chromium content not greater than 19 %, and is welded as such. Strength depends on the warm worked and precipitation treated condition, so the effect of the weld thermal cycle on local properties belongs in the WPS and PQR.
Applications
EN 10269 covers semi-finished products, bars and rods for fasteners with specified elevated or low temperature properties, and its requirements may also be applied to finished fasteners. That is where most demand for 1.4986 sits, in bolting scopes for high temperature service. Supplier literature for the grade also describes use in power generation and process plant, in superheater and boiler parts, heat exchangers, hot piping and reactor internals, where the alternative would be a more expensive nickel base alloy.
In our order book 1.4986 usually arrives as a forged blank for high temperature bolting stock, as ring and flange components in hot gas service, and as machined parts for boiler, turbine and petrochemical assemblies. For strongly chloride or sulphur bearing service, or above the guidance temperature of the grade, we will say so and quote an alternative from the nickel alloy range.
Forged product forms in 1.4986
Every item below is forged from a single piece of steel melted at this works. No welding, no casting, no purchased billet of unknown origin.
Seamless rolled rings
Rolled from a punched preform on a radial axial mill, rectangular or contoured section. Rings to OD 6000 mm, and from OD 50 mm by the upset and punch route.
Forged rings and retaining rings
Upset and punched rings for sections outside the ring mill envelope and for cases where heavy reduction is preferred to rolling.
Flanges, blocks, discs, plates
Weld neck, blind, slip-on, socket weld, lap joint, orifice and long weld neck patterns, plus solid discs, die blocks and forged plate.
Round, square, flat, hex bars
Forged bar stock as feedstock for high temperature bolting, machined valve parts and tooling. As-forged or peeled and turned.
Hollow bars, sleeves, bushings, cylinders
Hollow forged cylinders, casings, shells, hubs and housings, bored from solid forged blanks on a CNC deep hole drilling machine to 1600 x 10000 mm.
Tube sheets, covers, hubs
Solid forged discs and tube sheets for heat exchangers and pressure vessels, supplied proof-machined for volumetric inspection.
| Item | Limit | Set by |
|---|---|---|
| Seamless rolled ring outside diameter | to 6000 mm | 6 m radial axial ring mill, with 3 m and 1 m mills for smaller sizes |
| Minimum ring size | from OD 50 mm | Upset and punch route below ring mill range |
| Single piece weight | to 30000 kg | 60 t maximum heat size, 6300 t hydraulic press |
| Discs, tube sheets, blocks | to 5000 mm machined | 5000 mm swing vertical turning lathe |
| Shaft and bar turned length | to 14000 mm | C61160 horizontal lathe, 15 m well type furnace for vertical quench |
| Bored cylinders and hollow sections | to 1600 x 10000 mm | CNC deep hole drilling machine |
| Minimum order | 10 kg, no minimum piece count | Limit is by weight, so one-off parts are quotable |
| Lead time | 20 to 60 days | Standard stainless route at the lower end, remelted grades at the upper end |
Testing, certification, traceability
1.4986 carries a tight boron range and a carbon linked niobium minimum, so the chemistry has to be right at the furnace. This works melts its own steel. Analysis is verified in the melt shop by optical emission spectrometry to ASTM E415 and by infrared carbon and sulphur analysis to ASTM E1019, with handheld PMI for verification downstream. Mechanical testing runs on 600 kN and 300 kN universal machines to ASTM A370 and ISO 6892, with Charpy V-notch impact testing to minus 60 C, ultrasonic examination to ASTM A388 or EN 10228-3, magnetic particle examination to ASTM E709 and grain size metallography to ASTM E112.
Intergranular corrosion testing to ASTM A262, bench Brinell or Rockwell hardness where a portable instrument is not acceptable, and impact testing below minus 60 C are placed with an accredited third party laboratory and reported alongside the mill certificate. State these on the enquiry so they are scheduled before shipment. EN 10204 3.1 mill test certificates are supplied as standard. EN 10204 3.2 certificates witnessed by BV, DNV, LR, SGS, TUV or your own inspector are available on request. The works holds CCS, BV, DNV, LR and NK approvals, and traceability runs from the melt number through forging, heat treatment and machining to shipment.
1.4986 against the other austenitic grades of EN 10269
Where 1.4986 is unavailable or unsuitable, these are the austenitic grades alongside it in the same standard. The comparison is on specified chemistry and final condition, which is what drives substitution.
| Grade | Number | Cr % | Ni % | Mo % | Key additions | Final condition |
|---|---|---|---|---|---|---|
| X7CrNiMoBNb16-16 | 1.4986 | 15.5 to 17.5 | 15.5 to 17.5 | 1.60 to 2.00 | B 0.05 to 0.10; Nb+Ta 10 x C to 1.20 | +WW+P |
| X6NiCrTiMoVB25-15-2 | 1.4980 | 13.5 to 16.0 | 24.0 to 27.0 | 1.00 to 1.50 | Ti 1.90 to 2.30; V; B 0.0030 to 0.010 | +AT+P, solution 970 to 990 C, age 710 to 730 C |
| X10CrNiMoMnNbVB15-10-1 | 1.4982 | 14.0 to 16.0 | 9.0 to 11.0 | 0.80 to 1.20 | Mn 5.5 to 7.0; Nb 0.75 to 1.25; V; B | +AT+WW |
| X6CrNiMoB17-12-2 | 1.4919 | 16.5 to 18.5 | 10.0 to 13.0 | 2.00 to 2.50 | B 0.0015 to 0.0050 | +AT, 1020 to 1100 C |
| X6CrNiTiB18-10 | 1.4941 | 17.0 to 19.0 | 9.0 to 12.0 | - | Ti 5 x C to 0.80; B | +AT, 1070 to 1150 C |
| X3CrNiMoBN17-13-3 | 1.4910 | 16.0 to 18.0 | 12.0 to 14.0 | 2.00 to 3.00 | N 0.10 to 0.18; B 0.0015 to 0.0050 | +AT, 1020 to 1100 C |
1.4986 carries an order of magnitude more boron than the other boron bearing grades in the table. It is also the only grade in this selection whose final condition is warm worked and precipitation hardened rather than solution annealed, which is why its 500 MPa minimum proof strength sits far above the 200 to 280 MPa of the solution annealed austenitics. 1.4980, the A286 type grade, is the usual step up for higher strength at temperature; we forge it as A-286. For oxidation resistance at higher temperature with lower strength, AISI 310S or a stabilised grade such as AISI 347H is the more common choice. Above the range of any of these the answer is a nickel base alloy such as Incoloy 800H or Nimonic 80A.
Questions on 1.4986
What is 1.4986 steel?
1.4986, chemical designation X7CrNiMoBNb16-16, is a boron and niobium alloyed austenitic heat resistant steel standardised in EN 10269 for fasteners and components with specified elevated and low temperature properties. It contains 15.5 to 17.5 % chromium, 15.5 to 17.5 % nickel, 1.60 to 2.00 % molybdenum, 0.05 to 0.10 % boron and Nb+Ta from 10 x C up to 1.20 %. The former German designation under DIN 17240 was X8CrNiMoBNb16-16.
Is 1.4986 austenitic or martensitic?
Austenitic. EN 10269 lists it with the austenitic steels and EN 10088-1 classifies it as an austenitic stainless steel. Descriptions of 1.4986 as martensitic, or as an equivalent of UNS N07718, do not match the standards. The grade is precipitation treated, but the matrix stays austenitic.
What are the mechanical properties of 1.4986?
In the +WW+P condition up to 100 mm diameter EN 10269 requires Rp0.2 min 500 MPa, Rm 650 to 850 MPa, A min 16 % and ISO-V impact energy min 50 J at 20 C. The withdrawn DIN 17240 table for the same grade adds reduction in area min 40 % and DVM impact energy min 48 J.
What is the maximum service temperature?
EN 10269 tabulates strength to 650 C, where minimum Rp0.2 is 206 MPa and minimum Rm is 375 MPa. DIN 17240 gave 650 C as the guidance value for the normal upper limit in continuous operation for bolts, with up to 50 C more for nuts. Design in the creep range should use creep data agreed at order stage, not these short term values.
What is the UNS or AISI equivalent of 1.4986?
There is none. The nearest designations are the superseded German ones, X8CrNiMoBNb16-16 to DIN 17240 and material sheets WB 113/1 and WB 113/2 for heat resistant austenitic rolled and forged steel. Related EN 10269 austenitic grades with different chemistry are 1.4980, 1.4982, 1.4919, 1.4941 and 1.4910.
Can you forge 1.4986 rings and flanges, and in what sizes?
Yes. Jiangyin Jiangnan Metal melts and forges 1.4986 on one site in Jiangyin, Jiangsu Province, China. Seamless rings roll to OD 6000 mm, the heaviest single forging is 30 t on a 6300 t press, maximum heat size is 60 t, and rings start from OD 50 mm. Minimum order is 10 kg with no minimum piece count. Normal lead time is 20 to 60 days.
How is 1.4986 welded and machined?
For procedure qualification it sits in group 8.1 of ISO/TR 15608, austenitic steels with Cr not greater than 19 %. It work hardens, so machining calls for rigid setups, carbide tooling, generous coolant and controlled feeds. Strength comes from the warm worked and precipitation treated condition, so the effect of welding or re-heat-treatment on final properties has to be qualified.
What documentation is supplied?
EN 10204 3.1 as standard, EN 10204 3.2 witnessed by a classification society or a body such as SGS or TUV on request, with heat treatment charts, NDT reports, dimensional reports and PMI records. The works holds CCS, BV, DNV, LR and NK approvals.
How is 1.4986 priced?
There is no list price. Every 1.4986 forging is quoted against a drawing or a written specification, because cost follows the finished weight, the input weight before machining, the forging route, the heat treatment, the testing scope and the certification level. Minimum order is 10 kg with no minimum piece count.
Request a quotation for 1.4986 forgings
Quotations are prepared from a drawing or a written specification. Sending these six items in the first email removes a round trip and usually gets a price back within two working days.
| No. | Item | Example |
|---|---|---|
| 1 | Grade and standard edition | EN 10269 X7CrNiMoBNb16-16, 1.4986, +WW+P |
| 2 | Dimensions or drawing in PDF, DWG, DXF, STEP | OD 900 x ID 700 x H 180 mm ring |
| 3 | Quantity and expected repeat volume | 8 pieces, two batches per year |
| 4 | Delivery condition | As-forged, proof-machined or finish-machined |
| 5 | Heat treatment and testing | +WW+P, tensile at 550 C, UT to ASTM A388 |
| 6 | Certification and destination port | EN 10204 3.2 witnessed by DNV, Rotterdam |
Jiangyin Jiangnan Metal Co., Ltd. Open-die forging factory, steel melting works and ring rolling mill, operating since 1997.
Plant: 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. Customer audits, pre-shipment inspections and third party witness testing are welcome. Arrange visits by email so an English speaking engineer is available. Wuxi Shuofang International Airport is 30 km away and the Shanghai airports 160 km. Nearest export ports are Zhangjiagang and Shanghai.
References
Specified values on this page are taken from the standards and reference sources below. Where sources disagree, the disagreement is stated in the text.
- EN 10269, Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties. Composition, +WW+P mechanical values and elevated temperature strength tables, as published by the British Stainless Steel Association and by bolting supplier TorqBolt.
- EN 10088-1, Stainless steels, Part 1, List of stainless steels. Classification of 1.4986 as austenitic.
- DIN 17240, 1976, withdrawn, Heat resisting and highly heat resisting materials for bolts and nuts. Designation X8CrNiMoBNb16-16, reduction in area, DVM impact values, 650 C service guidance.
- German material sheets WB 113/1 and WB 113/2, 2001. Heat resistant austenitic rolled and forged steel X8 CrNiMoBNb 16 16, WN 1.4986.
- VIRGAMET and MakeItFrom grade databases. Indicative physical properties and ISO/TR 15608 welding group.
Prepared by the engineering and sales department, Jiangyin Jiangnan Metal Co., Ltd. Last reviewed . Data is for guidance and does not replace the standards. Consult the applicable edition of EN 10269 for contractual requirements.