X90CrMoV18 (1.4112 / AISI 440B) Forgings
High-carbon martensitic stainless steel. Forged round bars, seamless rolled rings, discs, blocks, sleeves and hollow bars, supplied worldwide from Jiangyin, China.
X90CrMoV18 is a high-carbon martensitic stainless steel specified in EN 10088-3 under material number 1.4112. It contains 0.85 to 0.95 % carbon, 17 to 19 % chromium, 0.90 to 1.30 % molybdenum and 0.07 to 0.12 % vanadium. It is delivered soft annealed at a maximum of 265 HB for machining and hardens to 58-60 HRC after austenitising at 1010-1070 °C and tempering at 150-200 °C. The nearest American grade is AISI 440B (UNS S44003). Applications include bearings and bearing races, valve seats and stems, pump parts, moulds and dies, cutlery, gauge blocks and surgical instruments. Jiangyin Jiangnan Metal Co., Ltd. produces X90CrMoV18 open-die forgings to customer drawings as bars, rings, discs, blocks and sleeves.
- Grade
- X90CrMoV18
- EN number
- 1.4112
- US equivalent
- AISI 440B
- UNS
- S44003
- Type
- Martensitic stainless
- Annealed
- max 265 HB
- Hardened
- 58-60 HRC
- Standard
- EN 10088-3
Chemical composition of X90CrMoV18 (EN 10088-3)
The chemical composition of X90CrMoV18 is specified in EN 10088-3:2014. Carbon combines with chromium, molybdenum and vanadium to form M23C6 and MC carbides. These carbides determine the wear resistance and edge retention of the hardened steel.
| C | Si | Mn | P | S | Cr | Mo | V |
|---|---|---|---|---|---|---|---|
| 0.85-0.95 | max 1.00 | max 1.00 | max 0.040 | max 0.030 | 17.0-19.0 | 0.90-1.30 | 0.07-0.12 |
Effect of the vanadium addition
The vanadium content of 0.07 to 0.12 % is the main difference in composition between X90CrMoV18 and AISI 440B. Vanadium forms fine MC carbides that restrict grain growth during austenitising. This gives a finer prior-austenite grain size and a more uniform carbide distribution, and improves wear resistance at a given hardness. The effect is most useful in heavy forged sections.
International equivalent grades for X90CrMoV18
X90CrMoV18 is cross-referenced to the designations listed below. Composition ranges differ slightly between standards. The mill certificate for the heat supplied should be checked against the design specification before substitution.
| Region / standard | Designation | Notes |
|---|---|---|
| Europe, EN 10088-3 | X90CrMoV18 / 1.4112 | Reference grade on this page |
| Germany, DIN 17440 | X90CrMoV18 | Superseded designation, same chemistry |
| USA, AISI / ASTM | 440B | Nearest equivalent, no mandatory V addition |
| USA, UNS | S44003 | C 0.75-0.95, Cr 16-18, Mo max 0.75 |
| Japan, JIS G4303 | SUS 440B | Close equivalent |
| China, GB/T 1220 | 9Cr18MoV | Chinese counterpart, V specified |
| Russia, GOST 5632 | 95Kh18MSh / 90Kh18MF | Close equivalent |
| France, AFNOR | Z90CDV18 | Close equivalent |
| Italy, UNI | X90CrMoV18 | Same designation |
X90CrMoV18 compared with the neighbouring 440-series grades
| Grade | EN no. | AISI | C, % | Max hardness | Characteristics |
|---|---|---|---|---|---|
| X70CrMo15 | 1.4109 | 440A | 0.60-0.75 | 54-56 HRC | Highest toughness and corrosion resistance, lowest wear resistance |
| X90CrMoV18 | 1.4112 | 440B | 0.85-0.95 | 58-60 HRC | Intermediate hardness and toughness, normal choice for forged bearing, valve and mould parts |
| X105CrMo17 | 1.4125 | 440C | 0.95-1.20 | 58-62 HRC | Highest hardness and wear resistance, lowest toughness, most difficult to machine |
Mechanical properties of X90CrMoV18
X90CrMoV18 is supplied soft annealed (condition +A) for machining and develops its service properties during hardening and tempering. The annealed hardness limit of 265 HB is specified in EN 10088-3.
| Condition | Hardness | Tensile strength Rm | 0.2 % proof Rp0.2 | Elongation A5 |
|---|---|---|---|---|
| Soft annealed (+A), delivery | max 265 HB | 760-900 MPa | 450-550 MPa | 12-18 % |
| Hardened, tempered 150-200 °C | 58-60 HRC | 2000-2200 MPa | 1800-1950 MPa | under 2 % |
| Hardened, tempered 250-350 °C | 55-57 HRC | 1900-2000 MPa | 1700-1800 MPa | approx. 2 % |
| Hardened, tempered 600-650 °C | 40-45 HRC | 1300-1450 MPa | 1100-1250 MPa | 5-8 % |
Values other than the annealed hardness are typical values for guidance and are not guaranteed acceptance values. Guaranteed properties are agreed per order and reported on the EN 10204 inspection certificate.
Physical properties of X90CrMoV18
| Property | Value | Unit |
|---|---|---|
| Density | 7.70 | g/cm3 |
| Modulus of elasticity | 215 | GPa |
| Thermal conductivity | 24 | W/(m·K) |
| Specific heat capacity | 460 | J/(kg·K) |
| Coefficient of thermal expansion, 20-100 °C | 10.4 x 10-6 | 1/K |
| Coefficient of thermal expansion, 20-400 °C | 11.5 x 10-6 | 1/K |
| Electrical resistivity | 0.65 | Ω·mm2/m |
| Magnetisability | Ferromagnetic in all conditions | |
| Maximum continuous service temperature | 250 | °C |
Heat treatment of X90CrMoV18
X90CrMoV18 is an air-hardening grade containing 18 % chromium. The heating rate and the interval between quenching and tempering both affect the result.
| Operation | Temperature | Cooling / hold | Result |
|---|---|---|---|
| Soft annealing | 840-870 °C (1545-1600 °F) | Furnace cool 15-25 °C/h to below 600 °C, then air | max 265 HB, machinable |
| Stress relieving | 600-650 °C (1110-1200 °F) | Hold 2-4 h, slow cool | Removes machining stress before hardening |
| Preheating | 600-650 °C, then 820-860 °C | Equalise at each stage | Limits cracking of heavy sections |
| Austenitising | 1010-1070 °C (1850-1960 °F) | Hold 20-30 min at temperature | Carbides taken into solution |
| Quenching | from austenitising temperature | Oil, warm forced air, or vacuum gas quench | Martensite and retained austenite |
| Sub-zero, optional | -75 to -195 °C | Hold 1-3 h, return to room temperature | Transforms retained austenite, 1-2 HRC higher, improved dimensional stability |
| Tempering, maximum hardness | 150-200 °C (300-390 °F) | 2 x 2 h minimum, air cool between | 58-60 HRC |
| Tempering, higher toughness | 250-350 °C | 2 x 2 h | 55-57 HRC |
Tempering range to avoid
Tempering between approximately 400 °C and 550 °C precipitates chromium carbides at the grain boundaries. This reduces the chromium content of the adjacent matrix and lowers corrosion resistance. It also reduces impact toughness. Temper at 150-200 °C where hardness is required, or at 600-650 °C where hardness is not required.
Practical points
- Transfer the part to the tempering furnace once it has cooled to 50-70 °C. Parts held at room temperature after quenching may crack.
- Austenitising above 1070 °C increases the retained austenite content and reduces hardness.
- Use a vacuum or protective-atmosphere furnace to prevent decarburisation and the associated loss of surface hardness.
Forging and hot working of X90CrMoV18
X90CrMoV18 is forged from ingot or continuous-cast bloom on open-die hammers and hydraulic presses. The hot working range is narrow. Working below the finish temperature causes cracking, and excessive soaking temperature coarsens the carbide network.
| Parameter | Recommended practice |
|---|---|
| Preheat | Charge below 500 °C, raise slowly to 760-820 °C and equalise |
| Forging start temperature | 1050-1150 °C (1920-2100 °F) |
| Finish temperature | Not below 900 °C (1650 °F) |
| Reduction ratio | Minimum 3:1 from ingot, 4:1 or higher for bearing and valve-trim quality |
| Cooling after forging | Slow cool in furnace or insulated pit, not in still air or draughts |
| Post-forge treatment | Full soft anneal at 840-870 °C after cooling, mandatory |
| Cold working | Only slightly cold workable, not recommended |
Effect of forging on carbide structure
In the as-cast condition X90CrMoV18 contains a coarse eutectic carbide network. Hot deformation breaks up this network and distributes the carbides through the section. A forged part therefore has higher toughness than a part machined from cast material of the same composition. Bearing races, valve seats and die blocks in this grade are normally produced as forgings for this reason.
Machining, grinding and welding X90CrMoV18
Machining
Machine X90CrMoV18 in the soft annealed condition, before hardening. Machinability is approximately 40 to 45 % of free-machining AISI 1212. Use rigid setups, sharp carbide or ceramic tooling, positive rake, moderate cutting speed and consistent feed. Interrupted feed work-hardens the cut surface. Chips are tough and stringy, so chip breakers are required. Allow 0.2 to 0.5 mm of grinding stock per surface for the distortion that occurs during hardening.
Grinding
Finishing after hardening is by grinding. Use soft-grade aluminium oxide or CBN wheels with adequate coolant and light passes. Overheating the surface during grinding re-austenitises a thin layer, which then transforms to untempered martensite on cooling and produces grinding cracks.
Welding
X90CrMoV18 is not normally welded. The carbon content of 0.9 % makes the heat-affected zone air-hardening and crack-sensitive. Where a repair weld is required, preheat to a minimum of 260 °C (500 °F) and maintain the preheat, use matching filler or an austenitic filler with high heat input, then anneal at 730-760 °C for approximately 6 hours with furnace cooling before re-hardening the part.
Corrosion resistance of X90CrMoV18
Corrosion resistance is moderate. A proportion of the chromium is combined as carbide rather than dissolved in the matrix, so the chromium available to form the passive film is lower than the nominal 17 to 19 %.
- Resistance is highest in the hardened and tempered condition with a ground or polished surface. Passivation in nitric acid improves it further.
- Resistance is lowest in the soft annealed condition and after tempering between 400 and 550 °C.
- Suitable media: fresh water, steam, mild atmospheres, alcohols, petroleum and petroleum products, many foodstuffs, dry gases.
- Unsuitable media: seawater, warm chloride-bearing solutions, reducing acids including hydrochloric and sulphuric acid. Continuous service above 250 °C is not recommended.
Applications of X90CrMoV18 forgings
X90CrMoV18 is selected for parts that require wear resistance and a hard, dimensionally stable surface under service conditions that would corrode a non-stainless tool steel.
- Ball bearings and races
- Valve seats and seat rings
- Valve stems
- Valve bodies and bonnets
- Pump parts and wear rings
- Nozzles
- Moulds and dies
- Plastic-moulding tooling
- Gauge blocks
- Cutlery and knife blades
- Surgical instruments
- Measuring instruments
- Pivot pins
- Wear plates and shafts
X90CrMoV18 forged shapes and size range
Jiangyin Jiangnan Metal Co., Ltd. produces X90CrMoV18 open-die forgings to customer drawings or to standard stock sizes, supplied rough machined, proof machined or finish machined.
| Product form | Typical size range | Notes |
|---|---|---|
| Forged round bar, shaft | 80-1200 mm diameter, length up to 6000 mm | Stepped and flanged shafts to drawing |
| Forged square, flat, hex bar | Thickness 40-800 mm, width up to 1500 mm | Cut to length |
| Seamless rolled ring | OD 200-4000 mm, wall 40-600 mm, height up to 1200 mm | Rectangular and profiled sections |
| Forged disc, block, plate | 100-2500 mm diameter, thickness 30-800 mm | Die blocks and mould blanks |
| Hollow bar, sleeve, bush | OD 100-1500 mm, ID from 60 mm | Bored and trepanned |
| Forged cylinder, housing, hub | To drawing | Casings, shells, barrels |
| Single-piece weight | 10 kg to 20 t | Heavier on enquiry |
Delivery conditions
Soft annealed (+A, max 265 HB) is the standard delivery condition for X90CrMoV18. Hardened and tempered, stress relieved, black forged, rough turned or bored, proof machined and finish machined conditions are available on request.
Testing, inspection and documentation
- Chemical analysis: spectrometric, ladle and product analysis
- Mechanical testing: tensile, hardness (HB and HRC), impact where applicable
- Ultrasonic examination to EN 10228-3, ASTM A388 or SEP 1921, class on request
- Dye penetrant and magnetic particle surface examination on request
- Metallographic examination: grain size, carbide distribution, banding
- Dimensional report against customer drawing
- Certification: EN 10204 type 3.1 mill certificate as standard, type 3.2 third-party certification on request
Frequently asked questions about X90CrMoV18
What is X90CrMoV18 steel?
X90CrMoV18 is a high-carbon martensitic stainless steel specified in EN 10088-3 under material number 1.4112. It contains 0.85 to 0.95 % carbon, 17 to 19 % chromium, 0.90 to 1.30 % molybdenum and 0.07 to 0.12 % vanadium. It is supplied soft annealed at a maximum of 265 HB for machining and is then hardened and tempered to 58-60 HRC for service.
Is X90CrMoV18 the same as AISI 440B?
X90CrMoV18 (1.4112) is the nearest European equivalent to AISI 440B / UNS S44003 and the two grades are normally interchangeable in design. X90CrMoV18 specifies a vanadium addition of 0.07 to 0.12 % and a higher minimum molybdenum content, which refines the carbide structure and improves wear resistance. Cross-acceptance should be confirmed against the mill certificate for the heat supplied.
What hardness can X90CrMoV18 reach?
X90CrMoV18 reaches 58-60 HRC after austenitising at 1010-1070 °C, quenching and tempering at 150-200 °C. A sub-zero treatment before tempering adds a further 1 to 2 HRC. In the soft annealed delivery condition (+A) the hardness is limited to a maximum of 265 HB for machining.
What is the difference between X90CrMoV18 (440B) and X105CrMo17 (440C)?
X105CrMo17 / 1.4125 / AISI 440C contains 0.95 to 1.20 % carbon, which gives a higher attainable hardness of 58-62 HRC and higher wear resistance but lower toughness. X90CrMoV18 / 440B has lower carbon, lower attainable hardness, higher toughness and better machinability and grindability. X90CrMoV18 is normally selected for larger forged sections, valve trim and heavier bearing components.
Can X90CrMoV18 be welded?
X90CrMoV18 is not normally welded. The carbon content of 0.9 % makes the heat-affected zone air-hardening and crack-sensitive. Where a repair weld is required, preheat to a minimum of 260 °C and maintain the preheat, use matching or austenitic filler with high heat input, then anneal at 730-760 °C for approximately 6 hours with furnace cooling before re-hardening.
How corrosion resistant is X90CrMoV18?
Corrosion resistance is moderate. With 17 to 19 % chromium and approximately 1 % molybdenum the grade resists fresh water, steam, mild atmospheres, alcohols, petroleum products and many foodstuffs. It is not suitable for seawater, warm chloride solutions or reducing acids. Resistance is highest in the hardened and tempered condition with a ground or polished surface and lowest in the annealed condition.
What forged shapes and sizes of X90CrMoV18 are available?
Jiangyin Jiangnan Metal Co., Ltd. supplies X90CrMoV18 as open-die forged round, square, flat and hex bars, hollow bars and sleeves, seamless rolled rings, discs, blocks, plates, shafts and stepped shafts. Typical ranges are round bar 80-1200 mm diameter, rings 200-4000 mm outside diameter and discs up to 2500 mm diameter. Enquiries: sales@steelforgepieces.com or +86-189-2135-9659.
What is X90CrMoV18 used for?
Typical applications are ball bearings and bearing races, valve seats, valve stems, valve bodies, bonnets and seat rings, pump parts, nozzles, pivot pins, moulds and dies, gauge blocks, cutlery and knives, surgical and measuring instruments, and other parts requiring high wear resistance together with moderate corrosion resistance.
Why is X90CrMoV18 supplied as a forging rather than as cast or rolled material?
In the as-cast condition this grade contains a coarse eutectic carbide network that reduces toughness. Open-die forging breaks up this network and redistributes the carbides through the section. Forging also allows production of large or non-standard sections, including rings up to 4000 mm outside diameter and discs up to 2500 mm diameter, which are outside the range of rolled bar.
Document information. Title: X90CrMoV18 (1.4112 / AISI 440B) Forgings. Publisher: Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China. Reviewed by the company technical department. Last reviewed: .
Source standards. EN 10088-3:2014, EN 10250-4:2000, ASTM A276/A276M, EN 10204:2004. Values other than the standardised composition and the annealed hardness are typical values for guidance and are not guaranteed acceptance criteria.
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