01
What 1.3813 is, and what it is not
1.3813 (X40MnCrN19) is a non-magnetisable austenitic manganese-chromium-nitrogen steel to SEW 390, with 0.30 to 0.50 percent carbon, 17.0 to 19.0 percent manganese, 3.00 to 5.00 percent chromium and 0.080 to 0.120 percent nitrogen. Manganese and nitrogen, not nickel, hold the structure austenitic, so the steel stays non-magnetic: relative permeability is at or below 1.01 after solution annealing and quenching, and at or below 1.03 after cold working.
It is not a stainless steel. EN 10020 sets the boundary for stainless at 10.5 percent chromium, and 1.3813 carries 3 to 5 percent. Several trader data sheets describe it as rust and acid resistant. That wording is a loose translation of the German group heading, and the chemistry does not support it. Specify a coating or a protected environment if the part will see moisture.
The reason the grade exists is electromagnetic, not structural. Put a ferromagnetic part inside a strong alternating field and it heats through eddy current and hysteresis losses, and it distorts the field the equipment depends on. A fully austenitic steel with permeability close to 1.0 does neither. Jiangyin Jiangnan Metal forges 1.3813 for exactly that situation, where the part has to carry load inside or beside a magnetic field.
Composition places 1.3813 in the 18Mn-4Cr to 18Mn-5Cr family, which was the standard material for generator rotor retaining rings through roughly 1960 to 1980. Schmiedewerke Krupp-Kloeckner recorded around 18,000 retaining rings produced over thirty years from a steel of 0.5 percent carbon, 18 percent manganese, 4.5 percent chromium and 0.1 percent nitrogen, which is the top of the SEW 390 carbon band and not its nominal 0.40 percent. The changeover to the 18Mn-18Cr replacement began in the mid 1970s, with the new alloy in service from 1978. The rest of that history matters when you buy the grade today, and section 07 covers it.
02
1.3813 chemical composition
Heat analysis limits to SEW 390, as published by the German mills and stockholders that carry the grade. Iron is the balance. Nickel and molybdenum are not alloyed to this grade and are not specified.
| C | Si | Mn | P | S | Cr | N | Fe |
|---|---|---|---|---|---|---|---|
| 0.30 to 0.50 | max. 0.80 | 17.00 to 19.00 | max. 0.100 | max. 0.030 | 3.00 to 5.00 | 0.080 to 0.120 | Balance |
A second set of limits circulates for this grade and it is not an error, it is a different document. Data sheets quoting Mn 18.0 to 20.0, Si max. 0.50, P max. 0.050 and S max. 0.015 are reproducing TLV 9384.01, a turbine builder technical delivery specification, which also carries its own mechanical requirements. The table above is SEW 390. Both are legitimate and they are not interchangeable, so name the document your drawing invokes. Jiangyin Jiangnan Metal melts its own steel, so the limits you need are set at the furnace and not argued about on an incoming billet certificate.
One figure needs a word of warning. The phosphorus ceiling of 0.100 percent in SEW 390 is a standard limit, not a target, and it is loose by the standards of any rotating or highly stressed component. Normal practice is far below it, and if your application warrants a tighter limit, say so on the enquiry: TLV 9384.01 sets 0.050 percent, and tighter can be agreed.
SEW 390 is a Stahl-Eisen-Werkstoffblatt issued by the German steel industry association, not a DIN or EN standard, and there is no EN designation for this grade. Data sheets writing it as DIN EN X40MnCrN19 are inventing a reference that does not exist.
The page this replaces showed carbon as 0.30 to 0.40. The upper limit in SEW 390 is 0.50, and carbon is the main strength contributor in this family, so the narrower range was worth correcting.
What each element is doing
- Manganese, 17 to 19 percent. The austenite stabiliser. It does the job nickel does in a 300 series stainless, at a fraction of the alloy cost, and it keeps the structure austenitic down to room temperature so no ferrite or martensite forms to carry magnetism.
- Nitrogen, 0.080 to 0.120 percent. Interstitial solid solution strengthening, and further austenite stabilisation. Nitrogen is the single line that separates 1.3813 from 1.3817 on paper, and it is why 1.3813 holds a higher yield strength at the same manganese and chromium levels.
- Carbon, 0.30 to 0.50 percent. More solid solution strengthening and more austenite stability. It is also the reason the steel has to be quenched from solution temperature rather than cooled slowly, because chromium carbides will otherwise form on the grain boundaries.
- Chromium, 3 to 5 percent. Added for strength and a small improvement in oxidation behaviour, not for corrosion resistance. At this level no passive film forms.
03
Mechanical properties by delivery condition
1.3813 is strengthened by cold work, not by hardening. An austenitic steel has no phase transformation to quench into, so quenching from 1000 to 1050 degrees Celsius softens it and puts the carbides back into solution. Strength above the solution annealed level comes from deformation, which is why SEW 390 lists three delivery conditions rather than a hardness range.
| Condition | Rp0.2, MPa | Rm, MPa | A5, percent | Impact, DVM | Permeability μr |
|---|---|---|---|---|---|
| Solution annealed and quenched | min. 295 | 740 to 930 | min. 45 | min. 124 J | max. 1.01 |
| Warm-cold worked | min. 390 | 830 to 1030 | min. 40 | min. 124 J | max. 1.01 |
| Cold worked | min. 490 | 830 to 1030 | min. 35 | min. 103 J | max. 1.03 |
Impact energy for this grade is quoted on the DVM specimen, not the ISO-V Charpy specimen. The two are not interchangeable and a DVM figure should not be compared directly against a Charpy V-notch requirement on a drawing. The neighbouring grade 1.3817 is published with ISO-V values instead, which is one more reason not to move numbers between the two data sheets.
For completeness: purpose-built retaining rings reach far higher figures than any row in the table, up to roughly 1200 MPa yield, by heavy cold expansion of a ring over a mandrel. That is a dedicated process route for one product, not a delivery condition you can order against SEW 390, and the toughness and permeability consequences are part of the ring maker's design. The numbers above are what a bar, a rolled ring or an open-die forging is certified to.
04
Physical and magnetic properties
| Property | Value | Comment |
|---|---|---|
| Density | 7.85 to 7.90 kg/dm³ | Walzwerke Einsal gives 7.85, Basedo Steel gives approximately 7.9 |
| Modulus of elasticity | approx. 191 000 MPa | Lower than the 200 to 210 GPa of ferritic steel, normal for a high manganese austenite |
| Electrical resistivity | approx. 0.70 Ω·mm²/m | High, which is part of why eddy current losses stay low |
| Relative permeability, quenched | max. 1.01 | Solution annealed and water quenched |
| Relative permeability, warm-cold worked | max. 1.01 | Strength raised without losing the 1.01 class |
| Relative permeability, cold worked | max. 1.03 | Cold deformation raises permeability |
| Magnetic behaviour | Paramagnetic | Fully austenitic, no ferrite, no martensite |
A generic modulus of 210 GPa appears on several aggregator pages for this grade. That is the default value those templates print for every steel and it does not match a high manganese austenitic structure. The figure to use for deflection calculations is approximately 191 GPa, from the German mill data.
Permeability is a property of the finished part, not of the heat. It is set by how the steel was worked and treated, it can be disturbed by local cold deformation during machining or straightening, and it is the one requirement on this grade that a mill certificate for chemistry alone will not satisfy. If a permeability limit is on the drawing, ask for it to be measured on the delivered part and reported, and name the measurement standard.
05
Forging and heat treatment practice
| Operation | Temperature | Cooling |
|---|---|---|
| Hot forming, forging and ring rolling | 850 to 1050 °C | Air, then solution treat |
| Solution annealing | 1000 to 1050 °C | Water or air |
| Hardening by quench and temper | Not applicable | Austenitic, no transformation to harden |
The forging window is narrow, and the finish temperature matters
Two hundred degrees of working range is not much, and the lower figure is a finish temperature rather than a soak temperature. Above about 1050 degrees Celsius a high manganese, high carbon austenite is prone to grain coarsening and to hot shortness; let the piece fall below about 850 degrees Celsius and it work hardens so rapidly that the press stalls and the surface tears. Heavy sections therefore need reheats, not one long pass, and the schedule has to be planned around the part. At Jiangyin Jiangnan Metal the melt shop, the presses, the ring mill and the fourteen heat treatment furnaces are on one site, so that schedule is set here, not inherited from a billet supplier.
Why the quench after solution treatment is not optional
With 0.30 to 0.50 percent carbon and 3 to 5 percent chromium in solution, slow cooling through roughly 600 to 900 degrees Celsius precipitates chromium carbides on the austenite grain boundaries. That costs toughness and ductility, and it can start a magnetic response at the boundaries, which defeats the point of the grade.
SEW 390 permits water or air cooling from solution temperature, and that permission is easy to misread. In a steel carrying up to 0.50 percent carbon, air cooling will not reliably suppress carbide precipitation through a heavy section; it is realistic for thin product only. Water quenching is the normal route for forgings. Section thickness sets whether the centre of a heavy piece actually cools fast enough, so for thick rings and large discs the section has to be agreed before the price, not after.
Machining and welding
Machining behaves like any strongly work hardening austenitic steel. Positive rake, a rigid set-up, a deliberate depth of cut and no dwelling in the cut: let the tool run under the hardened layer instead of rubbing on top of it. Welding is not a routine operation on this grade. High carbon combined with a Cr-Mn austenite gives both sensitisation and hot cracking risk, so any welded joint should be treated as a special case and agreed with a procedure before the order, not improvised at the shop.
06
Corrosion behaviour and service limits
1.3813 has no meaningful corrosion resistance and will rust. Chromium at 3 to 5 percent is below the level at which a passive chromium oxide film forms, so the steel behaves closer to an alloy structural steel than to a stainless one. Forgings are normally shipped with rust preventive oil and sealed packing, and parts in service need paint, plating or a dry environment.
This matters more than a coating specification, because the 18Mn-4Cr to 18Mn-5Cr family carries a documented stress corrosion cracking history in humid service. Retaining rings made from this family failed in service in Germany, Sweden and elsewhere from the late 1970s onward, attributed to stress corrosion cracking in the presence of moisture, and the industry response was a new alloy, not better sealing. If your application combines high sustained stress with any chance of condensation, chlorides or damp hydrogen, this is the wrong grade, and section 07 names the right one.
The published claim that 1.3813 is rust and acid resistant traces back to a German group description rendered into English by machine, and it has been copied across dozens of trading pages since. Jiangyin Jiangnan Metal does not repeat it, and will say so on an enquiry rather than let a customer design around it.
07
1.3813 against 1.3817 and 1.3816
Three grades sit next to each other in the non-magnetisable group and buyers move between them constantly. The table settles which is which.
| Item | 1.3813 X40MnCrN19 | 1.3817 X40MnCr18 | 1.3816 X8CrMnN18-18 |
|---|---|---|---|
| C | 0.30 to 0.50 | 0.30 to 0.50 | max. 0.12 |
| Si | max. 0.80 | max. 1.00 | max. 1.0 |
| Mn | 17.00 to 19.00 | 17.00 to 19.00 | 17.5 to 20.0 |
| Cr | 3.00 to 5.00 | 3.00 to 5.00 | 17.5 to 20.0 |
| N | 0.080 to 0.120 | max. 0.100 | 0.40 to 0.70 |
| Ni | Not specified | max. 1.00 | max. 1.00 |
| P | max. 0.100 | max. 0.060 | max. 0.06 |
| Rp0.2, quenched | min. 295 MPa | min. 280 MPa | min. 930 MPa, cold expanded |
| Impact specimen | DVM | ISO-V | ISO-V |
| SCC in humid service | Susceptible | Susceptible | Resistant |
| Product standard | SEW 390 | SEW 390 | SEW 390, ASTM A289 |
1.3816 figures are the composition published for that grade, alongside the ASTM A289 Grade 1 minimum yield. The two are close but not the same document: A289 calls for C max. 0.10, S max. 0.015, Ni max. 2.00 and N 0.45 to 0.80, so material certified to 1.3816 is not automatically compliant with A289 and the reverse is equally true. ASTM A289/A289M was withdrawn by ASTM in 2023 with no replacement, and it remains in wide use as a reference specification for existing generator fleets, which matters before it goes into a purchase order.
The 1.3817 row understates that grade in one respect. SEW 390 splits its requirements by test piece orientation: A5 minimum 35 percent longitudinal against 20 percent transverse, and ISO-V impact minimum 85 J longitudinal against 55 J transverse. A single headline figure hides that split, which matters on a forging where the critical direction is not the forging direction.
How to choose
- 1.3813 over 1.3817 when the drawing asks for the higher yield strength, because the nitrogen addition is what provides it. The two are otherwise the same steel, and 1.3817 has the tighter phosphorus limit and a nickel allowance.
- 1.3816 over both for a new generator retaining ring, or for any highly stressed non-magnetic part exposed to moisture. The 18Mn-18Cr alloy was developed specifically because the 18Mn-5Cr family cracked, and it replaced it across the industry.
- 1.3813 remains the right call for non-magnetic structural and machine parts in dry or protected service, for replacement parts that must match an existing 18Mn-5Cr specification, and where the 1.3816 nitrogen level is more alloy than the application needs.
08
Inspection and testing for non-magnetic forgings
Magnetic particle inspection does not apply to 1.3813, because the material is not ferromagnetic. ASTM E709 is written for ferromagnetic materials, and at a relative permeability capped at 1.03 no usable leakage field can be produced. Surface examination has to be liquid penetrant to ASTM E165 or EN ISO 3452-1, or eddy current. Any drawing note calling for MT on this grade is an error carried over from a ferritic part and should be raised before the order is placed.
That statement is often overstated, so it is worth being precise. It is not true that austenitic steels can never be magnetic particle tested: duplex and austenitic-ferritic grades, and austenitic castings carrying delta ferrite, often can be. It is true of 1.3813 specifically, which is exactly why SEW 390 puts a permeability ceiling on it.
The volumetric examination needs the same care, and here there is a gap in the standards that causes trouble on orders. Coarse grained austenitic material scatters and attenuates ultrasound in a way ferritic steel does not, so a procedure written for ferritic forgings will under-report on this grade.
EN 10228 has no part that covers this steel
EN 10228-3 is titled for ferritic and martensitic steel forgings, so it does not fit an austenitic grade. EN 10228-4 looks like the answer, but its scope is limited to forgings made from austenitic and austenitic-ferritic stainless steels, and 1.3813 is not stainless, as section 06 sets out. Part 4 also excludes turbine rotor and generator forgings by name, which is the application family this grade came from. Citing EN 10228-4 on a 1.3813 order will be queried at inspection.
The route that does fit is the ASTM pair. ASTM A388/A388M, Standard Practice for Ultrasonic Examination of Steel Forgings, is the general practice and carries no ferritic restriction. ASTM A745/A745M, Standard Practice for Ultrasonic Examination of Austenitic Steel Forgings, is written to be applied to forgings examined under A388 and adds the technique requirements that coarse austenitic grain demands. It says austenitic steel, not austenitic stainless steel, so it covers 1.3813. Specify A388 with A745, and state the acceptance class.
The page this replaces cited EN 10228-3, SEP 1921 and ASTM A388 alone. A388 on its own is not wrong, it is simply incomplete for an austenitic forging; EN 10228-3 and SEP 1921 are aimed at ferritic material and do not belong on this grade at all.
| Requirement | Method and reference | Note |
|---|---|---|
| Volumetric | Ultrasonic to ASTM A388/A388M with ASTM A745/A745M | EN 10228-3 is ferritic; EN 10228-4 is limited to stainless grades |
| Surface | Liquid penetrant to ASTM E165 or EN ISO 3452-1 | Magnetic particle does not apply, the steel is not ferromagnetic |
| Magnetic | Relative permeability to ASTM A342/A342M | Measure on the finished part, state the limit on the order |
| Chemistry | Optical emission spectrometry, ASTM E415 | Verified at the furnace, melt number traced to the part |
| Tensile and impact | ASTM A370 or ISO 6892 | Confirm DVM or ISO-V specimen on the order |
| Grain size | ASTM E112 | Relevant after the narrow-window forging schedule |
| Certification | EN 10204 3.1 as standard, 3.2 on request | 3.2 witnessed by BV, DNV, LR, SGS, TUV or your inspector |
Melting for this grade at Jiangyin Jiangnan Metal runs through the electric arc furnace with ladle refining and vacuum oxygen decarburisation, and through protective atmosphere electroslag remelting where a cleaner ingot is specified. Because the steel is melted on site, the nitrogen level can be aimed at the middle of the 0.080 to 0.120 percent band instead of accepted as delivered, and the certificate traces the part back to its melt number instead of stopping at a purchased billet.
Nitrogen control is the reason that matters on this particular grade. Nitrogen is what buys the proof strength and what holds the austenite stable, and it is lost to the atmosphere during melting unless the practice is set up to retain it. A forging shop working from bought billet has no way to correct a heat that came in at the bottom of the band.
09
Product forms and working envelope
Every item below is open-die forged or ring rolled from a single piece of steel, with no welding and no casting.
Seamless rolled rings
Ring rolled from a punched preform on the radial-axial mill, rectangular or contoured section, up to 6000 mm outside diameter.
Forged rings and sleeves
Upset and punched rings for sections outside the ring mill envelope, plus sleeves and bushings bored from solid.
Shafts, arbors and pins
Stepped and plain shafts, spindles and pins, with vertical quenching available for long parts in the 15 m well furnaces.
Bars, blocks and discs
Round, flat and square bars, blocks and solid forged discs, supplied as forged, proof machined or finish machined.
| Product | Limit | Set by |
|---|---|---|
| Seamless rolled rings | up to OD 6000 mm | 6 m radial-axial ring rolling mill |
| Rings below ring mill range | from OD 50 mm | Upset and punch route |
| Discs and blocks | up to Ø5000 mm machined | Ø5000 mm vertical turning lathe |
| Shafts | up to 14 000 mm turned length | Horizontal lathe, 15 m well furnace for vertical quench |
| Bored cylinders | up to Ø1600 × 10 000 mm | CNC deep-hole drilling machine |
| Single piece weight | up to 30 000 kg | 6300 t press, 60 t maximum heat size |
| Minimum order | 10 kg | No minimum piece count |
These are plant limits, not a promise for every grade. For 1.3813 the practical ceiling on a heavy section is usually the quench, not the press: the piece has to cool from 1000 to 1050 degrees Celsius fast enough through the section to keep carbides out of the grain boundaries. Send the section thickness with the enquiry and the heat treatment route will be confirmed with the price.
10
What to send with a 1.3813 enquiry
Six items give a firm price without a round trip. Quotations normally come back within two working days, and lead time runs 20 to 60 days depending on whether a remelting step is required.
| No. | Item | Example |
|---|---|---|
| 1 | Grade and any composition restriction | 1.3813 / X40MnCrN19, Mn 17.0 to 19.0, P max. 0.100 |
| 2 | Delivery condition | Solution annealed and quenched, or cold worked class |
| 3 | Permeability requirement | μr max. 1.01, measured to ASTM A342 on the finished part |
| 4 | Dimensions or drawing, and section thickness | OD 900 × ID 620 × H 180 mm, PDF or STEP |
| 5 | Testing | UT to ASTM A388 with A745, PT to ASTM E165, impact specimen type |
| 6 | Certificate and destination port | EN 10204 3.2 witnessed by DNV, Rotterdam |
Who makes these forgings
1.3813 forgings on this page are produced by Jiangyin Jiangnan Metal Co., Ltd., an integrated steel melting works and open-die forging factory operating in Jiangyin since 1997, holding CCS, BV, DNV, LR and NK classification society approvals and exporting to North America, Europe, the Middle East and Asia-Pacific.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Plant
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone
- +86 189 2135 9659
- sales@steelforgepieces.com
- Hours
- Monday to Saturday, 08:00 to 17:30 China Standard Time, UTC+8
11
Frequently asked questions about 1.3813
What is 1.3813 steel?
1.3813, designation X40MnCrN19, is a non-magnetisable austenitic manganese-chromium-nitrogen steel to SEW 390, containing 0.30 to 0.50 percent carbon, 17.0 to 19.0 percent manganese, 3.00 to 5.00 percent chromium and 0.080 to 0.120 percent nitrogen. Manganese and nitrogen rather than nickel hold the structure austenitic, so the steel stays paramagnetic with a relative permeability at or below 1.01 in the solution annealed and quenched condition.
Is 1.3813 a stainless steel?
No. EN 10020 requires at least 10.5 percent chromium for a steel to be classified as stainless, and 1.3813 contains 3 to 5 percent. It has no meaningful corrosion resistance and will rust in humid storage or service. Trader data sheets describing it as rust and acid resistant are repeating a loose translation of the German group heading, not a property of the steel.
Why is 1.3813 non-magnetic?
Its structure is fully austenitic, which is a face centred cubic phase with no ferromagnetic response, and manganese at 17 to 19 percent together with nitrogen at 0.08 to 0.12 percent keeps it austenitic down to room temperature. There is no ferrite and no martensite to carry magnetism. Relative permeability stays at or below 1.01 after solution annealing and quenching, and at or below 1.03 after cold working.
What are the mechanical properties of 1.3813?
SEW 390 gives three delivery conditions at room temperature. Solution annealed and quenched: Rp0.2 minimum 295 MPa, Rm 740 to 930 MPa, elongation A5 minimum 45 percent, DVM impact minimum 124 J. Warm-cold worked: Rp0.2 minimum 390 MPa, Rm 830 to 1030 MPa, A5 minimum 40 percent, DVM impact minimum 124 J. Cold worked: Rp0.2 minimum 490 MPa, Rm 830 to 1030 MPa, A5 minimum 35 percent, DVM impact minimum 103 J.
The impact values are quoted on the DVM specimen and should not be compared directly with an ISO-V Charpy requirement.
Can 1.3813 be hardened by quenching and tempering?
No. It is austenitic and has no phase transformation to harden, so quenching from the solution annealing range of 1000 to 1050 degrees Celsius softens the steel rather than hardening it. Strength above the solution annealed level is produced by cold or warm-cold deformation, which is why the standard lists delivery conditions instead of a hardness class.
Why must 1.3813 be quenched after solution annealing?
With 0.30 to 0.50 percent carbon and 3 to 5 percent chromium held in solution, slow cooling precipitates chromium carbides on the austenite grain boundaries. That reduces toughness and ductility and can produce a local magnetic response at the boundaries, which defeats the purpose of a non-magnetic grade. Water quenching from 1000 to 1050 degrees Celsius is the normal route, and section thickness has to be checked because the centre of a heavy piece must cool fast enough too.
Can magnetic particle inspection be used on 1.3813 forgings?
No, because the material is not ferromagnetic. ASTM E709 is written for ferromagnetic materials, and with relative permeability capped at 1.03 no usable leakage field can be produced. Surface examination has to be liquid penetrant testing to ASTM E165 or EN ISO 3452-1, or eddy current. A drawing note calling for magnetic particle inspection on this grade has usually been carried over from a ferritic part and should be corrected before the order is placed.
That applies to 1.3813 and not to austenitic steels in general. Duplex and austenitic-ferritic grades, and austenitic castings containing delta ferrite, can often be magnetic particle tested.
Which ultrasonic standard applies to 1.3813 forgings?
ASTM A388/A388M applied together with ASTM A745/A745M. A388 is the general practice for ultrasonic examination of steel forgings, and A745 adds the technique requirements for austenitic steel forgings, where coarse grain scatters and attenuates the beam.
Neither part of EN 10228 fits this grade. Part 3 is written for ferritic and martensitic steel forgings. Part 4 covers austenitic and austenitic-ferritic stainless steel forgings, and 1.3813 is not stainless; Part 4 also excludes turbine rotor and generator forgings by name. Specifying EN 10228-4 on a 1.3813 order will be queried at inspection.
What is the difference between 1.3813 and 1.3817?
Nitrogen. Both are non-magnetisable austenitic Mn-Cr steels with 0.30 to 0.50 percent carbon, 17.0 to 19.0 percent manganese and 3.00 to 5.00 percent chromium, but 1.3813 specifies nitrogen at 0.080 to 0.120 percent while 1.3817 caps it at 0.100 percent without a lower limit. The nitrogen raises the proof strength, so 1.3813 is specified at minimum 295 MPa in the quenched condition against minimum 280 MPa for 1.3817. Secondary differences are the phosphorus limit, tighter on 1.3817 at 0.060 percent, the nickel allowance of up to 1.00 percent on 1.3817, and the impact specimen, DVM for 1.3813 and ISO-V for 1.3817.
Is 1.3813 suitable for generator retaining rings?
Its composition is that of the 18Mn-4Cr to 18Mn-5Cr family that was the standard retaining ring material from the 1960s until the 1980s. That family was then replaced across the industry by the 18Mn-18Cr alloy, grade 1.3816 and specification ASTM A289, after stress corrosion cracking failures in the presence of moisture. For a new retaining ring the answer is 1.3816. For a replacement part that has to match an existing 18Mn-5Cr specification, or for a non-magnetic structural part in dry service, 1.3813 remains appropriate.
Does cold working 1.3813 affect its magnetic permeability?
Yes. SEW 390 allows a relative permeability of at most 1.01 in the solution annealed and quenched condition and in the warm-cold worked condition, but at most 1.03 after cold working. So the cold worked strength class, minimum 490 MPa proof strength, cannot be combined with the tightest permeability requirement. If a drawing asks for both, one of the two has to be relaxed, and that is better settled at enquiry stage than at final inspection.
Who supplies 1.3813 forgings?
Jiangyin Jiangnan Metal Co., Ltd. forges 1.3813 to customer drawings at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The works has melted and forged on one site since 1997, holds CCS, BV, DNV, LR and NK approvals, and supplies rings, seamless rolled rings, discs, shafts, bars, sleeves and bushings with EN 10204 3.1 or 3.2 certification. Enquiries go to sales@steelforgepieces.com or +86 189 2135 9659.
What is the minimum order quantity and lead time for 1.3813?
Minimum order is 10 kg with no minimum piece count, so a single small part is quotable and so is a one-off large ring. Normal lead time runs 20 to 60 days from order confirmation. Carbon, alloy and standard grades sit at the lower end; grades needing an electroslag or vacuum arc remelting step, and orders with third party witnessed inspection, sit at the upper end because the remelt cycle and the inspection appointment both have to be scheduled.
12
Where these numbers come from
Chemical and mechanical data on this page is taken from SEW 390 as published by German mills and stockholders carrying the grade, principally Walzwerke Einsal and Basedo Steel, cross-checked against the trader data sheets that circulate for X40MnCrN19. Where those sources disagree, the disagreement is stated in the text and not resolved silently. The retaining ring history is drawn from the published record of 18Mn-5Cr service failures and the development of the 18Mn-18Cr replacement alloy, including ASTM STP material from Schmiedewerke Krupp-Kloeckner and the ASME and EPRI reviews of retaining ring materials. Standards are cited by number and edition where the edition matters.
The plant data, equipment list and approvals are our own. Values for a specific order are confirmed on the inspection certificate for that order, which is the document that governs, not this page.
Citing this page
Jiangyin Jiangnan Metal Co., Ltd. "1.3813 (X40MnCrN19) Non-Magnetic Steel Forgings." steelforgepieces.com, reviewed 21 September 2026. https://www.steelforgepieces.com/Stainless-Steel/1.3813.html
Last reviewed: . Published by Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu Province, China.