9Cr18Mo Stainless Steel |102Cr17Mo | 440C | SUS440C Supplier In China
For Blades, Bearings & Precision Parts | MOQ 5 Tons | Bulk Supply
9Cr18Mo and 102Cr17Mo are the same type of steel. 9Cr18Mo is the old designation used in the Chinese national standard GB/T 1220-1992. 102Cr17Mo is the new designation adopted in the revised Chinese national standards GB/T 1220-2007 and GB/T 20878-2007.
9Cr18Mo(102Cr17Mo) is a high-carbon, high-chromium martensitic stainless steel, developed from the 95Cr18 (9Cr18) grade through the addition of molybdenum (Mo). Consequently, it exhibits superior hardness, wear resistance, high-temperature strength, tempering resistance, and corrosion resistance compared to 95Cr18 (9Cr18) steel. This steel also possesses good high-temperature dimensional stability, making it suitable for manufacturing plastic molds, bearings, surgical instruments, and measuring tools that operate under high loads, high wear, and corrosive conditions. As a ledeburitic steel, it is prone to non-uniform carbide segregation, which can adversely affect the service life of components. Therefore, it is imperative to control the processing parameters and select an appropriate processing ratio during hot working.
9Cr18Mo Steel Supply Overview
| Grade | GB 9Cr18Mo / 440C / SUS440C |
| Delivery Condition | Fully Annealed (Soft Condition for Machining) |
| Available Forms | Round Bar / Flat Bar / Plate / Forged Block |
| Monthly Production Capacity | Approx. 1000 metric tons |
| Recommended Export Quantity | Full 20GP container (~26 tons) |
| MOQ | 5 tons |
| Lead Time (With Ingot Stock) | Approx. 20 days |
| Lead Time (Fresh Melt) | 30–45 days |
| Lead Time (ESR Grade) | Approx. 60 days |
| Inspection | In-house UT team + Third-party inspection available |
| Documentation | MTC (EN 10204 3.1) + UT Report |
Why Global Distributors Source 9Cr18Mo from Aobo Steel
- Continuous monthly supply of around 1000 tons
- MOQ from 5 tons for wholesale orders
- Container-optimized bar and plate lengths
- Mixed sizes are supported for export loading
- Annealed delivery for downstream machining
- Stable sourcing through integrated supply chain partners
- UT inspection available to SEP 1921-82 D/d or E/e
- MTC and batch traceability with each shipment
- Heat number tracking for order control
- Black, turned, and polished surface options
- Bulk export packing for sea shipment
- Clear conversion path to the dedicated bulk supply page
Stable Production for Long-Term Bulk Supply
- Continuous monthly output of around 1000 tons
- Continuous production cycles for inventory replenishment
- ESR (Electro-Slag Remelting) is available upon request
- Stable alloy sourcing to reduce supply interruption risk
- Full batch traceability linked to the original heat number
Available 9Cr18Mo Steel Forms
Quality Control for Bulk Orders
Every batch of tool steel supplied by Aobo Steel is verified before shipment to ensure grade accuracy, internal soundness, and traceability for bulk orders.
- Chemical composition verified by a spectrometer
- Ultrasonic testing available (SEP 1921-82)
- Delivered in spheroidized annealed condition
- Mill Test Certificate (EN 10204 3.1) with heat number
- Dimensional and surface inspection before shipment
Export Packaging and Container Loading
- Professional seaworthy export packing
- 20GP loading optimized up to ~26 tons
- Mixed grades and mixed sizes supported
- Anti-rust protection for long sea transit
For international shipments, full-container loading is strongly recommended to ensure cost efficiency and smoother customs processing.
Compostion(GB/T 20878-2007)
| C | Cr | Mo | Ni | Si (≤) | Mn (≤) | P (≤) | S (≤) |
| 0.95 – 1.10 | 16.00 – 18.00 | 0.40 – 0.70 | -0.6 | 0.8 | 0.8 | 0.04 | 0.03 |
Equivalent Grades and Compositions
| Standard | Steel Grade | C | Cr | Mo | Ni | Si (≤) | Mn (≤) | P (≤) | S (≤) |
| Japan JIS | SUS440 | 0.95 – 1.20 | 16.00 – 18.00 | ≤(0.75) | -0.6 | 1 | 1 | 0.04 | 0.03 |
| USA ASTM | 440C / S4400C | 0.95 – 1.20 | 16.0 – 18.0 | ≤0.75 | — | 1 | 1 | 0.04 | 0.03 |
| International ISO | X105CrMo17 | 0.95 – 1.20 | 16.0 – 18.0 | 0.40 – 0.80 | — | 1 | 1 | 0.04 | 0.015 |
| Europe EN | X105CrMo17 / 1.4125 | 0.95 – 1.20 | 16.0 – 18.0 | 0.40 – 0.80 | — | 1 | 1 | 0.04 | 0.015 |
Critical Points of 9Cr18Mo(102Cr17Mo)
- Ac1≈815∼865℃: This is the lower critical temperature upon heating. It represents the temperature range at which austenite begins to form from the ferrite-carbide matrix.
- Ar1≈665∼765℃: This is the lower critical temperature upon cooling. It represents the temperature range in which the transformation of austenite to ferrite or pearlite is complete.
- Ms≈145℃: This is the Martensite start temperature. It is the temperature at which the transformation of austenite to martensite begins during rapid cooling (quenching).
Hot Froging Process of 9Cr18Mo(102Cr17Mo)
| Item | Heating Temperature/°C | Initial Forging Temp./°C | Final Forging Temp./°C | Cooling Method |
| Steel Ingot | 1130 ~ 1150 | 1080 ~ 1100 | 850 ~ 900 | Sand Cooling |
| Steel Billet | 1100 ~ 1120 | 1050 ~ 1080 | 850 ~ 900 | Sand Cooling |
Special attention should be paid to the hot-working process of 9Cr18Mo (102Cr17Mo) steel. It is recommended to use a cold-charged furnace for heating, and the heating rate should not be too fast, especially below 700°C. At the same time, the final forging temperature should be controlled at a higher level, and strict attention should be paid to the cooling conditions.
Heat Treatment of 9Cr18Mo(102Cr17Mo)
The processes for preliminary heat treatment are as follows:
- Recrystallization Annealing: Heat to 730∼- 750°C, then air cool.
- Annealing: Heat to 850∼- 870°C and soak for 4-6 hours. Subsequently, the furnace is cooled to below 600°C, then air-cooled. The hardness after annealing should be ≤ 255 HBW.
- Quenching: Heat to 1050∼- 1100∘°C, then oil quench. The as-quenched hardness should be ≥ 58 HRC.
- Tempering: Heat to 160∼- 180∘°C and soak for 3-5 hours. The final hardness after tempering should be ≥ 58 HRC.
The effect of quenching temperature and cold treatment on hardness
| Quenching Temperature (°C) | 1020 | 1040 | 1060 | 1080 | 1100 |
| Hardness after Conventional Quenching (HRC) | 58.5 | 58 | 61.5 | 61 | 61 |
| Hardness after Cold Treatment (HRC) | 60 | 60.5 | 62 | 63 | 64 |
Relationship between hardness and tempering temperature
| Tempering Temperature (°C) | Untempered | 100 | 200 | 300 | 400 | 500 | 600 | 700 | |
| 950°C Air Cooling | Hardness (HRC) / Quenching | 50 | 47 | 48 | 48 | 47 | 47 | 38 | 25 |
| 1000°C Air Cooling | 56 | 51.5 | 52 | 50 | 49 | 49 | 40.5 | 27 | |
| 1050°C Air Cooling | 58 | 56 | 56 | 53 | 52 | 52 | 43 | 29 | |
| 1100°C Air Cooling | 60.5 | 57 | 58 | 56 | 54 | 55 | 47 | 32 |
Mechanical Properties
Influence of Quenching Temperature and Cryogenic Treatment on Mechanical Properties
| Quenching Temperature /°C | Not Cryogenically Treated | After -75°C Cryogenic Treatment (held for 1h) | ||
| σbb/MPa | aK / J・cm⁻² | σbb/MPa | aK / J・cm⁻² | |
| 1020 | 3250 | 30 | 30 | 30 |
| 1040 | 3000 | 37 | 37 | 11 |
| 1060 | 3500 | 40 | 40 | 6 |
| 1080 | 2750 | 25 | 25 | 3 |
| 1100 | 2500 | 3 | 3 | 2.5 |
Corrosion Resistance
Corrosion Resistance of 102Cr17Mo (9Cr18Mo) Steel
| Heat Treatment Process | Hardness HRC | Medium Conditions | Corrosion Rate /g·(m²·h)⁻¹ | ||
| Medium | Mass Fraction (%) | Temperature/°C | |||
| 1050°C Oil Quenching | 61 | Sulfuric Acid | 2 | Boiling | 575.6 |
| Sulfuric Acid | 5 | 1003.9 | |||
| Nitric Acid | 40 | 1.15 | |||
| 1050°C Oil Quenching, 150°C Tempering for 1h | 60 | Sulfuric Acid | 2 | 502 | |
| Sulfuric Acid | 5 | 968.3 | |||
| Nitric Acid | 40 | 1.04 | |||
Get a Competitive Quote for 9Cr18Mo(102Cr17Mo) Stainless Steel
With over 20 years of forging expertise, Aobo Steel is your trusted partner for high-performance 9Cr18Mo(102Cr17Mo) stainless steel. We provide not just materials, but solutions. Leverage our deep industry knowledge and reliable supply chain for your project’s success.
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