Project Description
AISI/SAE 8620 (UNS G86200) is a low-alloy Ni-Cr-Mo carburizing steel engineered for components that demand a hard, wear-resistant case combined with a tough, ductile core. With a nominal carbon content of 0.20%, this grade exhibits excellent carburizing response, good machinability, and superior core toughness — properties that make it the most widely specified carburizing alloy across the OCTG downhole tooling, automotive transmission, and heavy equipment sectors.
Equivalent Grades of 8620
| Standard | Grade |
|---|---|
| AISI/SAE | 8620 / 8620H |
| ASTM | A322 / A29 / A534 / A519 |
| AMS | 6274 / 6276 / 6277 / 6375 |
| EN / DIN | 20NiCrMo2-2 / 1.6523 |
| JIS | SNCM220 (G4103) |
| GB | 20CrNiMoA (GB/T 3077) |
| BS | 805M20 / 805H20 |
| AFNOR | 20NCD2 / 22NCD2 |
| GOST | 20ХГНМ |
Chemical Composition (wt%)
| Element | AISI 8620 |
|---|---|
| C | 0.18–0.23 |
| Mn | 0.70–0.90 |
| Si | 0.15–0.35 |
| Cr | 0.40–0.60 |
| Ni | 0.40–0.70 |
| Mo | 0.15–0.25 |
| P max | ≤0.035 |
| S max | ≤0.040 |
Per ASTM A29 / A322; 8620H variant per ASTM A534 with adjusted hardenability bands.
8620 Steel Applications in Oil & Gas
With its outstanding carburizing response and core toughness, 8620 steel bar is extensively specified for carburized components across drilling, wellhead, and production equipment.
Supply Range — 8620 Steel Bar
SHUNFU METAL supplies AISI 8620 in hot-rolled, forged, and cold-drawn conditions. All bars are produced from EAF + LF + VD refined heats, subjected to 100% UT per SEP 1921 / EN 10228-3 Class 3, and traceable to heat number.
| Form | Dimension Range | Condition | Standard |
|---|---|---|---|
| Hot-Rolled Round | Φ10–350 mm | Black / Peeled & Polished | ASTM A29 / A322 |
| Forged Round | Φ90–1000 mm | Black / Rough-Turned | ASTM A29 |
| Cold-Drawn Round | Φ6–100 mm | Cold Drawn / Ground | ASTM A108 |
| Hot-Rolled Flat | Thk 3–120 x W 20–610 mm | Black | ASTM A29 |
| Forged Flat / Block | Thk 50–500 x W 100–1500 mm | Black / Rough-Machined | ASTM A29 |
| Seamless Tube Hollow Bar | OD 20–500 x WT 5–100 mm | Hot-Rolled / Cold-Drawn | ASTM A519 |
8620H variant (guaranteed hardenability per ASTM A304) available on request. Standard length: 3000–6000 mm, cut-to-length service available. Certificates: EN 10204 3.1 (standard) / 3.2 (TUV/third-party witnessed).
Mechanical Properties of 8620
Annealed Condition (870°C, Furnace Cool)
| Property | Value |
|---|---|
| Tensile Strength | ≥536 MPa (78 ksi) |
| Yield Strength (0.2%) | ≥385 MPa (56 ksi) |
| Elongation (A50) | ≥31% |
| Reduction of Area | ≥62% |
| Hardness | 149–197 HBW |
Carburized + Quenched & Tempered
| Condition / Section | Value |
|---|---|
| Surface Hardness | 58–62 HRC |
| Core Hardness | 35–47 HRC |
| Core Tensile (11 mm section) | 980–1270 MPa |
| Core Yield (11 mm section) | ≥785 MPa |
| Core Elongation (11 mm) | ≥9% |
| Charpy Impact (KV2) | ≥41 J |
Carburizing: 900–925°C, oil quench from 830–845°C, temper 150–175°C. Case depth: 0.5–2.3 mm per specification.
How SHUNFU METAL Produces 8620
Every 8620 bar from SHUNFU METAL is produced through a tightly controlled manufacturing route optimized for oil & gas applications:
| Stage | Process |
|---|---|
| 1. Melting | EAF + LF refining + VD degassing; optional ESR for enhanced cleanliness |
| 2. Forging/Rolling | 6,000-ton hydraulic press / GFM radial forge or hot rolling mill; ≥4:1 reduction ratio |
| 3. Normalizing | 870–930°C, air cool — refines grain structure for optimal machining and carburizing response |
| 4. UT Inspection | 100% volumetric per EN 10228-3 Class 3 / SEP 1921 |
| 5. Visual & Dimensional | 100% surface condition + dimensional check per ASTM A29 / A108 tolerance class |
| 6. Mechanical Testing | Tensile, hardness, impact, and grain size per heat + per size range |
| 7. Optional Carburizing Trial | Representative coupons carburized to verify case depth, surface hardness, and core response |
| 8. Certification | EN 10204 3.1 standard; 3.2 by TUV / LR / DNV / ABS upon request |
SHUNFU METAL’s ISO 9001:2015 certified quality system ensures full melt-to-product traceability. Jominy hardenability curves are supplied with every 8620H shipment.
