---
title: "03KH23N6 Forgings (03Х23Н6 / ZI68) | Rings, Flanges, Bars"
description: "03KH23N6 (03Х23Н6, ZI68) open-die forgings from Jiangyin Jiangnan Metal. GOST 5632 austenitic-ferritic steel: Cr 22-24, Ni 5.3-6.3, no molybdenum, no nitrogen."
canonical: "https://www.steelforgepieces.com/Stainless-Steel/03KH23N6.html"
manufacturer: "Jiangyin Jiangnan Metal Co., Ltd."
address: "No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China"
telephone: "+86 189 2135 9659"
email: "sales@steelforgepieces.com"
grade: "03KH23N6 / 03Х23Н6 / 03X23H6 / 03H23N6 / ЗИ68 / ZI68"
grade_standard: "GOST 5632-2014, austenitic-ferritic class, grade 5-2"
date_published: "2014-06-18"
date_modified: "2026-09-21"
language: "en"
---

# 03KH23N6 Forged Steel Components

Seamless rolled rings, forged rings, flanges, discs, tube sheets, bars and valve parts in GOST
grade 03Х23Н6. Melted, forged, solution annealed and machined in one works in Jiangyin, Jiangsu,
and shipped worldwide with EN 10204 3.1 certificates.

| | |
|---|---|
| GOST designation | 03Х23Н6 (works code ЗИ68) |
| Structural class | Austenitic-ferritic (duplex) |
| Chromium / nickel | 22.00 to 24.00 % / 5.30 to 6.30 % |
| Molybdenum, nitrogen | Neither is an alloying element |
| Solution anneal | 1000 to 1050 °C, water quench |
| Max service temperature | about 300 °C |

## Summary

03KH23N6 is the transliteration of 03Х23Н6, a Russian GOST 5632 corrosion-resistant steel of the
austenitic-ferritic (duplex) class, also carried under the works code ЗИ68 / ZI68. It contains
22.00 to 24.00 % chromium and 5.30 to 6.30 % nickel, with carbon held to 0.030 % maximum.

03Х23Н6 contains no molybdenum and no nitrogen as alloying elements. GOST 5632 normalises neither
for this grade, and the grade name itself carries no letter for nitrogen. This is the main difference
between 03Х23Н6 and the modern duplex grades, and several published datasheets for 03KH23N6 state it
incorrectly.

In the solution annealed condition to GOST 7350-77, minimum yield strength is 345 MPa, minimum
tensile strength 590 MPa and minimum elongation 25 %. It is specified for strength and for
resistance to knife-line attack in welds. It is not a seawater or sour-service grade: calculated on guaranteed
chromium, its PREN is about 22 to 24.

Jiangyin Jiangnan Metal Co., Ltd. forges 03Х23Н6 into seamless rolled rings, forged rings, flanges,
discs, tube sheets, bars, sleeves and valve components at its integrated melting and open-die forging
works at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The steel is
melted on site, so the chemistry is set for the part rather than accepted from a billet supplier.
Call +86 189 2135 9659 or email sales@steelforgepieces.com.

## What is 03KH23N6 steel?

03KH23N6 is the Latin transliteration of the Russian grade 03Х23Н6, listed in GOST 5632 among the
steels of the austenitic-ferritic class. The mill code ЗИ68 appears on older certificates and on
material supplied against TU 14-1-1541-75.

The name states the chemistry. Under the GOST naming rules the leading figures give
carbon in hundredths of a percent, so 03 means 0.030 % maximum. Х is chromium and the 23 after it is
the nominal chromium content. Н is nickel and the 6 after it is the nominal nickel content. There are
no further letters, and under GOST 5632 a letter in the middle of a grade name declares an element
such as nitrogen. The absence of one here is not an omission in the published tables, it is what the
standard specifies.

The structure is roughly half ferrite and half austenite, and that two-phase structure gives the
grade its strength: minimum yield strength is 345 MPa against 205 MPa for an austenitic grade such as
08Х18Н10Т. GOST itself recommends 03Х23Н6 as a higher-strength substitute for 08Х18Н10Т and 03Х18Н11
in chemical process equipment.

The grade was developed for welded vessels and apparatus in nitric acid, ammonium nitrate and adipic
acid plants, where the combination of very low carbon and a duplex structure gives good resistance to
intergranular attack and to knife-line attack in the weld fusion boundary. It also appears in
equipment operating in radioactive environments that is not itself in contact with the aggressive
medium, and as a welding consumable composition.

## Designations, transliterations and aliases

Cyrillic Х and Н look like Latin X and H, so this grade reaches suppliers under at least five
different spellings. They are all the same steel, and an enquiry sent under any of them is understood.

| Form | Written as | Where it comes from |
|---|---|---|
| GOST, Cyrillic | 03Х23Н6 | The official grade designation |
| Latin lookalike | 03X23H6 | Cyrillic characters typed on a Latin keyboard |
| Transliteration | 03KH23N6 | Х rendered as KH, Н as N. The most common export spelling |
| Alternative transliteration | 03H23N6 | Х rendered as H |
| Works code | ЗИ68 / ZI68 | Zlatoust works designation, used in TU documents |
| By chemical elements | 03Cr23Ni6 | Used in some cross-reference tables |

Do not confuse 03Х23Н6 with 03Х22Н6М2 (ЗИ67). The two grades were developed together and sit next to
each other in GOST 5632 as grades 5-2 and 5-3. 03Х22Н6М2 carries 1.80 to 2.50 % molybdenum; 03Х23Н6
carries none. If a drawing calls for molybdenum in a GOST duplex, the grade wanted is almost certainly
03Х22Н6М2.

## A correction to the data published for this grade, including ours

An earlier version of this page described 03KH23N6 as a 22 % chromium, 3 % molybdenum,
nitrogen-alloyed duplex and printed a composition table with molybdenum 2.30 to 3.50 % and nitrogen
0.10 to 0.22 %. Those figures belong to duplex 2205 (1.4462 / UNS S31803 and S32205), not to 03Х23Н6.
The mechanical figures on that page, 0.2 % proof stress of 450 MPa and tensile strength of 620 MPa,
were also the 2205 bar values.

The table below is taken from GOST 5632-2014 table 1, grade 5-2, and from GOST 7350-77 and
TU 14-1-1541-75 for the plate limits. The change is stated here rather than made silently, because a
buyer who ordered against the old figures needs to know which numbers moved.

A certificate showing 2 to 3 % molybdenum does not satisfy a 03Х23Н6 drawing, and a certificate
showing no molybdenum does not satisfy a 2205 drawing. If the enquiry says 03KH23N6 and the
application is chloride-bearing or sour service, the drawing grade may not suit the duty. Send the
service conditions with the enquiry so they can be checked before any steel is melted.

## Chemical composition of 03KH23N6

Weight percent, iron balance.

| Standard | C | Si | Mn | Cr | Ni | S | P | Mo | Ti | Cu | N |
|---|---|---|---|---|---|---|---|---|---|---|---|
| GOST 5632-2014 (5-2) | max 0.030 | max 0.40 | 1.00–2.00 | 22.00–24.00 | 5.30–6.30 | max 0.020 | max 0.035 | residual max 0.30 | residual max 0.20 | residual max 0.30 | not specified |
| GOST 7350-77 (plate) | max 0.03 | max 0.4 | 1–2 | 22–24 | 5.6–6.3 | max 0.02 | max 0.035 | max 0.3 | max 0.05 | max 0.3 | not specified |
| TU 14-1-1541-75 (ЗИ68) | max 0.03 | max 0.4 | 1–2 | 22–24 | 5.6–6.3 | max 0.02 | max 0.035 | not stated | max 0.05 | not stated | not specified |

Residual element rules that come with the grade: under GOST 5632-2014 clause 6.3, titanium in steels
not alloyed with titanium is limited to 0.20 %, and by agreement between maker and buyer 03Х23Н6 is
supplied with titanium at 0.05 % maximum. Under clause 6.7, residual molybdenum is limited to 0.30 %
and, on the buyer's order, to 0.10 % maximum for this grade specifically. GOST 7350-77 permits the
finished product to deviate by plus 0.40 % on silicon, plus 0.005 % on sulphur, plus or minus 0.20 %
on nickel and plus 0.50 % on chromium. State on the enquiry if your drawing needs the tighter
molybdenum limit, because it is a melt-shop decision that cannot be made after the heat is cast.

## Is 03KH23N6 the same as duplex 2205, 2304 or 329?

No, and the published cross-references disagree with each other. Some Russian equivalence tables map
03Х23Н6 to 1.4362 / X2CrNiN23-4 / UNS S32304 on the strength of the chromium and nickel figures.
Others map it to 1.4460 / AISI 329 / UNS S32900, on the grounds that it belongs to the older
generation of duplex grades that predate nitrogen alloying. Neither is an exact match, and no standard
declares them interchangeable.

| Element | 03Х23Н6 (GOST 5632) | 1.4362 / S32304 | 1.4462 / S32205 | 1.4460 / S32900 |
|---|---|---|---|---|
| C max | 0.030 | 0.030 | 0.030 | 0.05 |
| Si max | 0.40 | 1.00 | 1.00 | 1.00 |
| Mn | 1.00–2.00 | max 2.00 | max 2.00 | max 2.00 |
| Cr | 22.00–24.00 | 22.0–24.5 | 21.0–23.0 | 25.0–28.0 |
| Ni | 5.30–6.30 | 3.5–5.5 | 4.5–6.5 | 4.5–6.5 |
| Mo | residual only | 0.10–0.60 | 2.50–3.50 | 1.30–2.00 |
| N | not specified | 0.05–0.20 | 0.10–0.22 | 0.05–0.20 |
| Cu | residual only | 0.10–0.60 | not specified | not specified |
| PREN, approx. | 22–24 | 23–29 | 32–33 | 30–36 |

### Why the nickel is higher and the nitrogen is missing

One figure in the table above runs against expectation. 03Х23Н6 carries more nickel than 2304 does,
yet it is the more ferritic of the two. Nitrogen accounts for that. In the standard austenite-balance
formulae nitrogen counts roughly thirty times as strongly as nickel, so 2304 with 0.05 to 0.20 %
nitrogen has a higher austenite potential than 03Х23Н6 with nothing but its extra nickel. The nickel
in 03Х23Н6 partly compensates for the absent nitrogen, but does not fully replace it.

The consequence shows up in a weld. Nitrogen diffuses quickly at high temperature and re-forms
austenite in the heat-affected zone as the joint cools, while nickel diffuses too slowly to do the
same work in the seconds available. A nitrogen-free duplex therefore leaves a ferrite-rich heat-affected zone unless heat input
and interpass temperature are controlled, which is why GOST practice for this family prescribes a
solution anneal after welding on fabrications where corrosion performance in the weld region governs.

## Mechanical properties of 03KH23N6

Room temperature, solution annealed and water quenched.

| Product and condition | Rp0.2 min | Rm min | A5 min |
|---|---|---|---|
| Plate 4.0–50.0 mm hot rolled and 4.0–5.0 mm cold rolled to GOST 7350-77, water quenched from 1030–1050 °C | 345 MPa (50 ksi) | 590 MPa (86 ksi) | 25 % |
| Hot-rolled plate 4–11 mm to TU 14-1-1541-75, water quenched from 1000–1025 °C | 343 MPa (50 ksi) | 588 MPa (85 ksi) | 25 % |
| Reference: austenitic 08Х18Н10Т, solution annealed | 205 MPa | 510 MPa | 40 % |

The third row shows why the grade is specified. At the same chromium level a duplex structure
delivers roughly seventy percent more yield strength than an austenitic grade, which for a pressure vessel
means a thinner wall, less weld metal and a lighter fabrication. Elongation falls from 40 % to 25 %,
which is ample for a pressure part and tight enough to matter if the part is to be cold formed after
machining.

GOST does not specify impact energy for 03Х23Н6, and no hardness range is laid down for the grade.
Where a drawing calls for Charpy values or a hardness band on a forging, they are agreed at order stage
and tested on a representative test piece. Impact testing down to minus 60 °C runs in our own
laboratory; below that it is placed with an accredited third party. Impact energy falls off in any
duplex grade as the ferrite phase becomes the controlling phase at low temperature, so a cryogenic
requirement should be raised before the grade is fixed.

## Physical properties

GOST publishes no separate physical property table for 03Х23Н6. The figures below are those of
08Х22Н6Т, the closest published austenitic-ferritic grade at the same chromium and nickel level, and
are given for preliminary work only. Do not use them in a design calculation without confirming them
against the governing code.

| Property | 20 °C | 200 °C | 300 °C | Confidence |
|---|---|---|---|---|
| Density | 7,700 kg/m³ | not published | not published | Indicative |
| Modulus of elasticity | 203 GPa | 193 GPa | 181 GPa | Indicative |
| Thermal conductivity | not published | 16 W/(m·K) | 18 W/(m·K) | Indicative |
| Electrical resistivity | 740 nΩ·m | not published | not published | Indicative |
| Magnetic response | Ferromagnetic. The ferrite phase makes any duplex steel attracted to a magnet. | | | Certain |

The magnetic response is stated here because it surprises buyers who expect a stainless grade to be
non-magnetic. It also has a practical consequence on inspection: magnetic particle
examination works on this grade, where it cannot be used on a fully austenitic steel.

## Forging and heat treatment of 03KH23N6

| Operation | Temperature | Cooling |
|---|---|---|
| Start of forging | 1150 °C (2100 °F) | not applicable |
| Finish of forging | not below 850 °C (1560 °F) | Air |
| Solution anneal, GOST 7350-77 | 1030–1050 °C (1885–1920 °F) | Water |
| Solution anneal, TU 14-1-1541-75 | 1000–1025 °C (1830–1875 °F) | Water |
| Anneal to restore resistance to intergranular attack | 1050 ± 25 °C | Water or air |
| Range to avoid on cooling and in service | 600–950 °C and 280–500 °C | Pass through, do not hold |

### Why the absence of molybdenum makes this grade easier to forge heavy

Molybdenum and tungsten strongly accelerate sigma phase formation in duplex steels. Sigma is a hard,
brittle chromium-rich intermetallic that precipitates between roughly 600 and 950 °C, and a few
percent of it will halve the impact toughness of a forging. In 2205, with 2.5 to 3.5 % molybdenum,
sigma can appear in minutes at the nose of the curve, so heavy 2205 sections have to be forged and
quenched quickly.

03Х23Н6 carries molybdenum only as a residual, capped at 0.30 % and at 0.10 % if the order asks for
it. Sigma formation is correspondingly sluggish. In a heavy ring or a thick disc, where the core cools
more slowly than the surface, the grade tolerates section thicknesses that give a molybdenum-bearing
duplex trouble. This offsets the lower PREN and is one reason the grade is still specified for large
welded vessel components rather than replaced outright by 2205.

The forging must be quenched, not air cooled. GOST specifies water quenching from the solution anneal
for this grade. Slow cooling through 600 to 950 °C precipitates chromium carbides at the
ferrite-austenite boundaries and undoes the low-carbon chemistry the grade was designed around.

## Welding 03KH23N6

Published GOST practice for 03Х23Н6 names manual argon-arc welding with a non-consumable electrode,
with or without filler, and automatic submerged-arc welding. The grade is also used as a welding
consumable composition in its own right.

- No preheat required
- Control heat input and interpass temperature
- Argon-arc, with or without filler
- Automatic submerged-arc welding
- Solution anneal after welding where weld corrosion performance governs
- Ferrite count on the weld and heat-affected zone where specified

With no nitrogen in the base metal, austenite reformation in the heat-affected zone depends on nickel
diffusion, which is slow. High heat input and a long time in the ferritic range leave a coarse,
ferrite-rich heat-affected zone with reduced toughness and reduced corrosion resistance. The remedy is
a controlled, moderate heat input and, where the weld must match the base metal in service, a post-weld
solution anneal at 1050 ± 25 °C followed by a quench.

Where a fabricator cannot solution anneal a completed assembly, and the joint is in the corrosive path,
the grade choice should be reviewed before the joint is accepted. A nitrogen-bearing duplex such as
2205 or 2304 recovers its weld-zone austenite without a post-weld heat treatment, which is what
nitrogen alloying was introduced to achieve.

## Corrosion behaviour and service limits

03Х23Н6 resists intergranular corrosion well. Carbon at 0.030 % maximum leaves too little to form
chromium carbides in quantity, and the duplex structure interrupts the continuous austenite grain
boundary network that carries intergranular attack in a single-phase steel. Published Russian practice
specifically credits the grade with improved resistance to knife-line attack in welded joints, which
is the failure mode that takes stabilised austenitic grades such as Х18Н9Т and Х18Н10Т out of service
in nitric acid plants.

The grade is not suited to chloride service. Pitting and crevice resistance track the PREN number, and on the chromium guaranteed by GOST, with no molybdenum and no nitrogen to contribute,
03Х23Н6 sits at about 22 to 24. Duplex grades are normally expected to carry a PREN above 32 before
seawater is considered, and above 40 for warm seawater.

A second correction to the earlier version of this page: that page listed seawater desalination plants,
subsea and deepwater offshore production systems, and downhole service in sour gas wells among the
applications. None of those is appropriate for a PREN 22 to 24 steel with no molybdenum. 03Х23Н6 is
also not a listed material in NACE MR0175 / ISO 15156 for sour service. For chloride or sour duty the
grades to look at are SAF 2205, SAF 2507 or A182 F55.

### Temperature limits

The ferrite phase in any duplex steel decomposes on long holding between roughly 280 and 500 °C, with
the worst of it near 475 °C. The steel becomes harder and markedly less tough, and the change is not
reversible in service. Published GOST application notes cap the closely related duplex grades 08Х22Н6Т
and 03Х22Н6М2 at 300 °C for this reason, and the same limit should be applied to 03Х23Н6.

At the cold end, duplex grades lose impact toughness well before austenitic grades do, because the
ferrite phase has a ductile-to-brittle transition. Where a low-temperature requirement exists, state it
with the enquiry so the test temperature can be agreed and tested rather than assumed.

## Testing and certification

| Test | Standard | Where it is run |
|---|---|---|
| Chemical analysis | ASTM E415, GOST 12344 to 12365 | In-house optical emission spectrometer and carbon-sulphur analyser |
| Positive material identification | Handheld alloy analyser | In-house |
| Tensile | ASTM A370, ISO 6892 | In-house, 600 kN and 300 kN machines |
| Impact, to −60 °C | ASTM A370 | In-house, pendulum machine with low-temperature bath |
| Ultrasonic examination | EN 10228-4, ASTM A745 | In-house, full-digital flaw detectors |
| Magnetic particle | ASTM E709 | In-house. Applicable because duplex is ferromagnetic |
| Intergranular corrosion | GOST 6032, ASTM A262 | Accredited third-party laboratory |
| Ferrite phase balance | ASTM A923, ASTM E562 | Accredited third-party laboratory |
| Grain size and microstructure | ASTM E112 | In-house metallography |

Use the right ultrasonic standard. The earlier version of this page cited EN 10228-3 and ASTM A388.
Both are written for ferritic and martensitic forgings. An austenitic-ferritic forging has a coarse,
acoustically anisotropic structure that scatters and attenuates the beam, and results obtained under a
ferritic procedure are not reliable. The correct standards are EN 10228-4, which covers austenitic and
austenitic-ferritic stainless steel forgings, and ASTM A745. State the acceptance class on the enquiry
so the probe frequency and calibration block are set before the part is machined for inspection.

EN 10204 3.1 material certificates are supplied as standard, covering melt analysis, mechanical results
and heat-treatment records. EN 10204 3.2 certificates witnessed by a classification society or by a
third-party inspection body are available on request. The works holds CCS, BV, DNV, LR and NK
classification society approvals.

## Forged shapes supplied in 03KH23N6

- **Seamless rolled rings** — radial-axial rolled, rectangular or contoured section, outside diameter to 6,000 mm
- **Forged rings** — upset and punched, for sections outside the ring-mill envelope
- **Flanges** — weld neck, blind, slip-on, lap joint and orifice flanges to drawing
- **Discs and tube sheets** — solid forged discs, tube sheets and vessel covers, proof-machined for inspection
- **Bars and blocks** — round, flat and square forged bar, die blocks and machining stock
- **Sleeves and hollow bars** — bushings, shells and heavy-wall cylinders bored from solid
- **Valve components** — bodies, bonnets, seat rings, stems and blocks for chemical service
- **Custom forgings** — any profile forged to a 2D drawing or 3D model

Minimum order is 10 kg with no minimum piece count, so both a single small part and a one-off large
ring can be quoted.

## Forging capability for this grade

Jiangyin Jiangnan Metal Co., Ltd. has operated as an integrated melting works and open-die forge in
Zhouzhuang Town, Jiangyin, since 1997. Unlike a forging shop that buys billet, the plant melts its own
steel, so for a grade with tight residual limits such as 03Х23Н6 the chemistry is set at the furnace
rather than accepted as delivered.

| | |
|---|---|
| Melting | Electric arc furnace, ladle furnace and vacuum oxygen decarburisation for stainless and duplex grades. Maximum heat size 60 tonnes |
| Forging | Hydraulic open-die presses of 6,300 t, 4,000 t and 2,000 t; hammers from 750 kg to 5 t |
| Ring rolling | Radial-axial mills of 6 m, 3 m and 1 m. Rings from outside diameter 50 mm to 6,000 mm |
| Heaviest piece | 30 tonnes single-piece weight |
| Heat treatment | 14 furnaces on site, including car-bottom furnaces with a working chamber to 8,000 × 2,000 × 2,000 mm and two 15 m well-type furnaces for vertical quenching of long parts |
| Machining | Vertical lathes to Ø5,000 mm swing, horizontal lathes to 14,000 mm, CNC deep-hole drilling to Ø1,600 × 10,000 mm |
| Delivery condition | As-forged with allowance, proof-machined for volumetric inspection, or finish-machined to drawing |
| Certification | EN 10204 3.1 as standard, 3.2 witnessed on request. CCS, BV, DNV, LR and NK approvals |
| Minimum order | 10 kg, no minimum piece count |
| Lead time | 20 to 60 days from order confirmation |
| Quotation | Returned within two working days |
| Plant address | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
| Contact | +86 189 2135 9659, sales@steelforgepieces.com |

## Applications of 03KH23N6 forgings

- Welded apparatus for chemical process plant
- Vessel shells, heads and flanges in nitric acid service
- Ammonium nitrate production equipment
- Adipic acid plant components
- Heat exchanger tube sheets and covers
- Valve bodies and internals for chemical duty
- Higher-strength replacement for 08Х18Н10Т and 03Х18Н11 parts
- Equipment connections in radioactive environments not contacting the medium
- Welding consumable and electrode stock

Chloride and sour-service applications are deliberately absent, for the reason given in the corrosion
section.

## How to order 03KH23N6 forgings

1. **Send the drawing or dimensions.** Email a drawing in PDF, DWG, DXF or STEP, or the plain
   dimensions, to sales@steelforgepieces.com. For a ring, outside diameter, inside diameter and height
   are enough to start.
2. **State the grade standard you are buying to.** Confirm whether the order is against GOST 5632
   grade 03Х23Н6 or against an equivalent such as 1.4362 or UNS S32304. They are not interchangeable
   and the certificate has to name the standard the drawing calls for.
3. **Confirm heat treatment, testing and certification.** Specify the delivery condition, the
   EN 10204 certificate level, and any intergranular corrosion testing to GOST 6032 or ASTM A262,
   ultrasonic examination to EN 10228-4 or ASTM A745, ferrite counting, or third-party witness
   inspection.
4. **Receive the quotation.** You get forging weight, unit price, lead time and Incoterms within two
   working days. Minimum order is 10 kg and normal lead time runs 20 to 60 days.

## Frequently asked questions about 03KH23N6

### What is 03KH23N6 steel?

03KH23N6 is the transliteration of the Russian GOST grade 03Х23Н6, a corrosion-resistant steel of the
austenitic-ferritic or duplex class, also known by the works code ЗИ68 or ZI68. It contains 22.00 to
24.00 % chromium and 5.30 to 6.30 % nickel with carbon limited to 0.030 % maximum. It is used for
welded chemical process equipment, particularly in nitric acid, ammonium nitrate and adipic acid
production, and is recommended by GOST as a higher-strength substitute for the austenitic grades
08Х18Н10Т and 03Х18Н11.

### Does 03KH23N6 contain molybdenum?

No. Molybdenum is not an alloying element in 03Х23Н6. GOST 5632-2014 permits it only as a residual at
0.30 % maximum, and clause 6.7 allows the buyer to order the grade with residual molybdenum at 0.10 %
maximum. Any datasheet showing 2 to 3 % molybdenum for this grade has copied the composition of duplex
2205. The GOST grade that does carry molybdenum in this family is 03Х22Н6М2, at 1.80 to 2.50 %.

### Is 03KH23N6 nitrogen alloyed?

No. GOST 5632 does not specify nitrogen for 03Х23Н6, and under the GOST naming rules a letter in the
middle of a grade name declares an element such as nitrogen. 03Х23Н6 has no such letter. By comparison,
the neighbouring GOST duplex grade 03Х22Н5АМ3 carries the letter А and is specified with 0.08 to
0.20 % nitrogen. The absence of nitrogen is the main practical difference between 03Х23Н6 and every
modern duplex grade, and it affects how the heat-affected zone of a weld behaves.

### What is the equivalent of 03KH23N6 in EN or UNS?

There is no exact equivalent, and published cross-reference tables disagree. Some map 03Х23Н6 to
1.4362 / X2CrNiN23-4 / UNS S32304 on the chromium and nickel figures, others to 1.4460 / AISI 329 /
UNS S32900 as an older nitrogen-free duplex. Neither match is exact: 2304 is nitrogen and copper
alloyed and carries less nickel, while 329 carries far more chromium and 1.3 to 2.0 % molybdenum. If
the drawing calls for GOST 03Х23Н6, order against GOST 5632 and have the certificate name that
standard.

### What are the mechanical properties of 03KH23N6?

In the solution annealed and water quenched condition to GOST 7350-77, minimum yield strength is
345 MPa, minimum tensile strength 590 MPa and minimum elongation 25 %. Under TU 14-1-1541-75 for
hot-rolled plate of 4 to 11 mm the corresponding values are 343 MPa, 588 MPa and 25 %. GOST specifies
no impact energy and no hardness range for this grade, so where a drawing calls for them they are
agreed at order stage and tested on a representative test piece.

### What heat treatment is applied to 03KH23N6 forgings?

Forging starts at 1150 °C and finishes no lower than 850 °C. The part is then solution annealed and
water quenched, at 1030 to 1050 °C under GOST 7350-77 or 1000 to 1025 °C under TU 14-1-1541-75. Where
resistance to intergranular corrosion has to be restored, the anneal is run at 1050 plus or minus
25 °C. Slow cooling is not acceptable: the part must pass quickly through 600 to 950 °C, where
chromium carbides and sigma phase form.

### Can 03KH23N6 be used in seawater or sour service?

No. Calculated on the chromium guaranteed by GOST, with no molybdenum and no nitrogen contributing,
the PREN of 03Х23Н6 is only about 22 to 24. Duplex grades are normally expected to exceed PREN 32
before seawater is considered. The grade is also not a listed material in NACE MR0175 / ISO 15156 for
sour service. For chloride-bearing or sour duty, use SAF 2205, SAF 2507 or A182 F55 instead.

### What is the maximum service temperature of 03KH23N6?

About 300 °C. The ferrite phase in any duplex steel decomposes on prolonged holding between roughly
280 and 500 °C, with the effect strongest near 475 °C, and the resulting loss of toughness is not
reversible in service. Published GOST application notes cap the closely related duplex grades
08Х22Н6Т and 03Х22Н6М2 at 300 °C, and the same limit applies here.

### Is 03KH23N6 magnetic?

Yes. The ferrite phase makes 03Х23Н6 ferromagnetic, as it does every duplex stainless steel. This
surprises buyers who expect a stainless grade to be non-magnetic, but it has a useful consequence for
inspection: magnetic particle examination can be used on this grade, where it cannot be used on a fully
austenitic steel such as 08Х18Н10Т.

### Which ultrasonic standard applies to 03KH23N6 forgings?

EN 10228-4 or ASTM A745. Both are written for austenitic and austenitic-ferritic stainless steel
forgings. EN 10228-3 and ASTM A388 are written for ferritic and martensitic forgings and are not
appropriate, because the coarse, acoustically anisotropic structure of a duplex forging scatters and
attenuates the beam and gives unreliable results under a ferritic procedure.

### How is 03KH23N6 welded?

Published GOST practice names manual argon-arc welding with a non-consumable electrode, with or
without filler, and automatic submerged-arc welding. No preheat is required. Because the grade contains
no nitrogen, austenite reformation in the heat-affected zone depends on slow nickel diffusion, so heat
input and interpass temperature have to be controlled to avoid a ferrite-rich heat-affected zone. Where
weld corrosion performance governs, the fabrication is solution annealed at 1050 plus or minus 25 °C
and quenched after welding.

### Why is 03KH23N6 easier to forge in heavy sections than 2205?

Molybdenum strongly accelerates sigma phase formation, the brittle chromium-rich intermetallic that
precipitates between roughly 600 and 950 °C. Duplex 2205 carries 2.50 to 3.50 % molybdenum and forms
sigma quickly, which makes heavy sections difficult because the core of a thick part cools slowly
through that range. 03Х23Н6 carries molybdenum only as a residual, so sigma formation is far more
sluggish and the grade tolerates section thicknesses that give a molybdenum-bearing duplex trouble.

### What forged shapes are available in 03KH23N6?

Seamless rolled rings to 6,000 mm outside diameter, forged rings, weld neck and blind flanges, discs,
tube sheets and vessel covers, round, flat and square bars, blocks, sleeves, bushings, hollow bars, and
valve bodies, bonnets, seat rings and stems. Custom profiles are forged to a 2D drawing or 3D model.
Minimum order is 10 kg with no minimum piece count.

### Who supplies 03KH23N6 forgings?

Jiangyin Jiangnan Metal Co., Ltd. is an integrated steel melting works and open-die forging factory at
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997.
It melts its own steel and forges 03Х23Н6 to drawing for export worldwide, with EN 10204 3.1
certificates as standard. Contact +86 189 2135 9659 or sales@steelforgepieces.com. Quotations are
returned within two working days and minimum order is 10 kg.

### What certificates are supplied with 03KH23N6 forgings?

EN 10204 3.1 material certificates are supplied as standard, covering melt analysis, mechanical test
results and heat-treatment records. EN 10204 3.2 certificates witnessed by a classification society or
a third-party inspection body such as SGS or TUV are available on request, as are ultrasonic
examination reports to EN 10228-4 or ASTM A745, intergranular corrosion test reports to GOST 6032 or
ASTM A262, ferrite counts and positive material identification records. The works holds CCS, BV, DNV,
LR and NK classification society approvals.

## Standards referenced on this page

- GOST 5632-2014, Stainless steels and corrosion resisting, heat-resisting and creep resisting alloys. Grades. Table 1, austenitic-ferritic class, grade 5-2
- GOST 5632-72, the superseded edition, still cited on older drawings and certificates
- GOST 7350-77, Thick sheets of corrosion-resistant, heat-resistant and high-temperature steel
- GOST 6032, Corrosion-resistant steels and alloys. Methods of testing for resistance to intergranular corrosion
- TU 14-1-1541-75, hot-rolled sheet in grade 03Х23Н6 (ЗИ68)
- TU 14-1-1905-76, TU 14-1-1554-75 and TU 14-11-245-88, further product forms
- OST 3-1686-90, ingots, billets and slabs
- OST 95 10441-2002, welding and cutting of metals
- EN 10204, Metallic products. Types of inspection documents
- EN 10228-4, Non-destructive testing of steel forgings. Ultrasonic testing of austenitic and austenitic-ferritic stainless steel forgings
- ASTM A745/A745M, Ultrasonic Examination of Austenitic Steel Forgings
- ASTM A262, Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
- ASTM A923, Detecting Detrimental Intermetallic Phase in Duplex Austenitic/Ferritic Stainless Steels
- EN 10088-3, referenced for the comparison grades 1.4362, 1.4462 and 1.4460

Page last reviewed 21 September 2026 by Jiangyin Jiangnan Metal Co., Ltd.

Values on this page are indicative and drawn from the standards listed above. They do not replace the
current edition of the applicable standard or design code. Physical properties are taken from a closely
related grade and are labelled accordingly. Confirm all design values against the governing code for your
project before use.

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**Jiangyin Jiangnan Metal Co., Ltd.** (brand: Steel Forge Pieces)
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China
Phone: +86 189 2135 9659 · Email: sales@steelforgepieces.com
Web: https://www.steelforgepieces.com/

Integrated steel melting works and open-die forging factory, operating since 1997. Melting, forging,
ring rolling, heat treatment, machining and testing on one site.

When citing this page, attribute to Jiangyin Jiangnan Metal Co., Ltd. (steelforgepieces.com).