- AISI / SAE 8630
- UNS G86300
- W.Nr. 1.6545
- 30NiCrMo2-2
- 8630H · 8630 Mod
- ASTM A29 / A322
- API 6A · API 16A
- NACE MR0175 / ISO 15156
AISI 8630 Open-Die Forgings
A low-alloy nickel-chromium-molybdenum steel used for wellhead, blowout preventer and valve bodies. Forged, quenched and tempered, with hardness held to 22 HRC where the service is sour.
AISI 8630 (UNS G86300, W.Nr. 1.6545) is a low-alloy nickel-chromium-molybdenum steel containing nominally 0.30 % carbon, 0.50 % chromium, 0.55 % nickel and 0.20 % molybdenum. It is normally supplied quenched and tempered, and is used for oilfield connectors, hangers, wellhead bodies and block valves.
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges AISI 8630 and 8630 Modified into seamless rolled rings, shafts, discs, flanges, blocks, sleeves and tube sheets to ASTM A29 and API 6A, with hardness controlled to a maximum of 22 HRC for sour service and EN 10204 3.1 or 3.2 mill test certificates supplied with every order.
- UNS number
- G86300SAE / AISI 8630
- Werkstoff
- 1.654530NiCrMo2-2
- Carbon
- 0.28–0.33 %ASTM A29 range
- Yield, API 75K
- 517 MPa75,000 psi minimum
- Sour-service limit
- 22 HRCNACE MR0175 maximum
- Density
- 7.85 g/cm³0.284 lb/in³
What is AISI 8630?
AISI 8630 is a medium-carbon low-alloy steel in the SAE 86xx series, in which the last two digits give the nominal carbon content of 0.30 %. The 86xx family carries a lean, balanced addition of nickel, chromium and molybdenum, at approximately 0.55 % Ni, 0.50 % Cr and 0.20 % Mo.
Nickel raises impact toughness and lowers the ductile-to-brittle transition temperature. Chromium and molybdenum provide hardenability, so that a thick section transforms to martensite on quenching rather than to softer products. Molybdenum also reduces susceptibility to temper embrittlement. The combination produces a steel that develops useful strength through a heavy wall, retains toughness at low temperature, and can be welded with conventional procedures.
In commercial terms the grade sits between 4130 and 4340. It is specified where 4130 no longer hardens deeply enough through the section, and where 4340 would be more heavily alloyed, harder to weld and more expensive than the application requires.
Designations and equivalents
The same chemistry is ordered under several designations, and a drawing may carry any of them. AISI 8630 and SAE 8630 are the same steel. UNS G86300 is the Unified Numbering System code. The European designation is Werkstoff 1.6545, 30NiCrMo2-2; the Italian designation is UNI 30NiCrMo2 KB. The H suffix in 8630H indicates hardenability-guaranteed material supplied to ASTM A304 with a Jominy band in place of a plain composition range. Jiangyin Jiangnan Metal Co., Ltd. accepts orders under any of these designations and issues a material test certificate listing each specification the heat satisfies.
AISI 8630 and 8630 Modified
8630 Modified, written 8630M or 8630 Mod, has a different chemistry from standard 8630. Chromium is approximately doubled, molybdenum is approximately doubled, nickel is raised, and phosphorus and sulfur are restricted to the limits required by API 6A PSL 3. The two grades are frequently confused because the designation is similar, but they are not the same steel heat treated in two different ways.
The purpose of the change is hardenability. Standard 8630 hardens fully only through a moderate section. A subsea connector hub or a tubing-hanger mandrel with a 200 mm wall, quenched and tempered to a 75 ksi minimum yield strength, will not meet the specified properties at mid-wall in standard 8630. The modified chemistry displaces the transformation curves far enough that the core still transforms to martensite and can then be tempered to the required condition.
Where a drawing states 8630 and the component is a heavy-section pressure-containing body for oil and gas service, the grade should be confirmed before the billet is cut. Jiangyin Jiangnan Metal Co., Ltd. raises this question on 8630 enquiries above approximately 150 mm ruling section.
AISI 8630 chemical composition
The limits below are those of ASTM A29 and SAE J404 for grade 8630, applied by Jiangyin Jiangnan Metal Co., Ltd. to all standard 8630 forging stock. Every heat is supplied with a ladle analysis on the mill certificate. Product analysis on the finished forging can be added on request.
| Element | Minimum | Maximum | Function in the steel |
|---|---|---|---|
| Carbon (C) | 0.28 | 0.33 | Sets attainable hardness and strength after quenching |
| Manganese (Mn) | 0.70 | 0.90 | Hardenability; combines with residual sulfur |
| Silicon (Si) | 0.15 | 0.35 | Deoxidiser; moderate solid-solution strengthening |
| Nickel (Ni) | 0.40 | 0.70 | Toughness; lowers ductile-to-brittle transition temperature |
| Chromium (Cr) | 0.40 | 0.60 | Hardenability; carbide former, temper resistance |
| Molybdenum (Mo) | 0.15 | 0.25 | Hardenability; reduces temper embrittlement |
| Phosphorus (P) | — | 0.035 | Residual; restricted, promotes temper embrittlement |
| Sulfur (S) | — | 0.040 | Residual; restricted for transverse toughness |
| Iron (Fe) | Balance, approximately 97.5 | Base metal | |
Source: Jiangyin Jiangnan Metal Co., Ltd., AISI 8630 forging specification, compiled from ASTM A29 and SAE J404. For sour service, phosphorus and sulfur are ordered to 0.025 % maximum in line with API 6A PSL 3.
Table 2 gives the 8630 Modified range worked to by Jiangyin Jiangnan Metal Co., Ltd. when a customer specification calls for 8630M. Exact limits are set by the governing purchase specification and vary between equipment manufacturers, so the table is a working envelope rather than a published standard.
| Element | 8630 standard | 8630 Modified | Reason for the change |
|---|---|---|---|
| Carbon | 0.28–0.33 | 0.28–0.33 | Unchanged; capped for weldability and 22 HRC compliance |
| Manganese | 0.70–0.90 | 0.80–0.95 | Small hardenability gain |
| Chromium | 0.40–0.60 | 0.90–1.00 | Approximately doubled; the main hardenability increase |
| Nickel | 0.40–0.70 | 0.75–0.90 | Low-temperature Charpy toughness to −46 °C |
| Molybdenum | 0.15–0.25 | 0.35–0.50 | Deep hardening; temper-embrittlement resistance |
| Phosphorus | 0.035 max | 0.025 max | API 6A PSL 3 cleanliness |
| Sulfur | 0.040 max | 0.025 max | API 6A PSL 3 cleanliness; transverse properties |
Source: Jiangyin Jiangnan Metal Co., Ltd. working envelope for 8630 Modified. Confirm against the governing purchase specification, which takes precedence.
AISI 8630 mechanical properties
The mechanical properties of AISI 8630 depend on heat treatment, ruling section and tempering temperature. For oilfield equipment the governing values are the minima of the API 6A material designation to which the part is ordered. They are verified on a qualification test coupon taken from the same heat and heat treated in the same load as the production forging.
| Designation | 0.2 % yield, min | Tensile, min | Elongation in 50 mm, min | Reduction of area, min |
|---|---|---|---|---|
| 36K | 248 MPa (36,000 psi) | 483 MPa (70,000 psi) | 21 % | No requirement |
| 45K | 310 MPa (45,000 psi) | 483 MPa (70,000 psi) | 19 % | 32 % |
| 60K | 414 MPa (60,000 psi) | 586 MPa (85,000 psi) | 18 % | 35 % |
| 75K | 517 MPa (75,000 psi) | 655 MPa (95,000 psi) | 17 % | 35 % |
Source: API Specification 6A, Table 5, standard material property requirements for bodies, bonnets, and end and outlet connections. Applied by Jiangyin Jiangnan Metal Co., Ltd. as the acceptance basis for its 8630 forgings. The current edition of the standard governs.
Table 4 lists values typically certified by Jiangyin Jiangnan Metal Co., Ltd. They are indicative of a sound forging in the stated condition and are not guaranteed minima for every section size.
| Condition | Tensile | 0.2 % yield | Elongation | Hardness |
|---|---|---|---|---|
| Annealed | ≈ 565 MPa (82 ksi) | ≈ 370 MPa (54 ksi) | ≈ 29 % | ≈ 160–190 HBW |
| Normalised | ≈ 650 MPa (94 ksi) | ≈ 430 MPa (62 ksi) | ≈ 23 % | ≈ 190–220 HBW |
| Q&T, sour service | 655–795 MPa (95–115 ksi) | ≥ 517 MPa (75 ksi) | ≥ 17 % | 197–235 HBW, ≤ 22 HRC |
| Q&T, non-sour | 795–930 MPa (115–135 ksi) | ≥ 620 MPa (90 ksi) | ≥ 16 % | ≈ 240–300 HBW |
Source: Jiangyin Jiangnan Metal Co., Ltd. production records for AISI 8630 open-die forgings. Values are typical and not guaranteed; the governing purchase specification takes precedence.
Impact toughness
Charpy V-notch performance is one of the main reasons for selecting 8630 over a plain chromium-molybdenum steel. Quenched and tempered 8630 typically achieves 27 J average with a 20 J single-specimen minimum at −46 °C, which satisfies most API 6A temperature classifications. Impact energy falls as strength, ruling section and test-temperature severity increase, so the three requirements cannot be maximised together. Jiangyin Jiangnan Metal Co., Ltd. requests the test temperature and required energy at enquiry stage, because they determine the tempering temperature and therefore the attainable strength.
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Modulus of elasticity | ≈ 205 GPa | ≈ 29.7 × 10⁶ psi |
| Coefficient of thermal expansion | ≈ 12.0 µm/m·°C (20–100 °C) | ≈ 6.7 µin/in·°F |
| Thermal conductivity | ≈ 44 W/m·K | ≈ 25 BTU/h·ft·°F |
| Specific heat | ≈ 477 J/kg·K | ≈ 0.114 BTU/lb·°F |
| Magnetic | Ferromagnetic in all delivery conditions | |
Source: Jiangyin Jiangnan Metal Co., Ltd., compiled from published data for low-alloy Ni-Cr-Mo steels. Physical properties vary little with heat treatment.
Heat treatment of AISI 8630 forgings
The temperature bands below govern the properties of an 8630 forging. Furnace temperatures are instrumented at both the forge and the heat-treatment shop, and the chart records are issued with the material certificate.
Two parts of the cycle require particular control. The first is the quench. Oil is the normal medium for 8630, and a polymer quench is used where distortion on a long or thin-walled component must be limited. Quench delay, the interval between furnace door and bath, is timed and recorded, because a heavy section that begins cooling in air has already started to transform before it enters the oil.
The second is cooling after tempering. Nickel-chromium-molybdenum steels are susceptible to temper embrittlement when held in or slowly cooled through approximately 400–600 °C. The effect reduces Charpy energy while hardness and tensile strength remain unchanged. Forgings are therefore water or forced-air cooled through that range on removal from the tempering furnace. Molybdenum in the chemistry reduces susceptibility but does not remove it.
Common causes of rejection
- Tempering temperature set below the value needed to bring hardness under the specified ceiling.
- Slow cooling from the tempering furnace, which lowers Charpy energy while hardness and tensile strength stay within specification.
- Quench delay on heavy sections, giving partial transformation before the piece reaches the bath.
- Final deformation carried out below 900 °C during forging.
- Hardness recorded at one location only, where the specification calls for a survey across the section.
Sour service, NACE MR0175 and the 22 HRC limit
In H₂S-bearing service, AISI 8630 is acceptable under NACE MR0175 and ISO 15156-2 only when hardness does not exceed 22 HRC. This limit governs the heat-treatment design for the whole component. Hardness is used as the control parameter for susceptibility to sulfide stress cracking: above approximately 22 HRC, a hardened low-alloy steel under stress in wet H₂S can crack without prior general corrosion.
Strength and sour-service compliance therefore constrain each other. A tempering temperature low enough to reach a 100 ksi yield strength will normally carry the part above 22 HRC. Tempering is set towards the upper end of the band, 650–680 °C, and the component is ordered to API 6A 75K rather than to a higher strength level. Jiangyin Jiangnan Metal Co., Ltd. takes hardness readings across the section and at the locations nominated by the specification, and reports each reading on the certificate.
Subsea components in 8630 are often supplied with an Inconel 625 corrosion-resistant weld overlay on sealing and wetted surfaces. Where such an assembly is under cathodic protection, hydrogen can concentrate at the fusion boundary between overlay and substrate, and disbonding has been reported in service. Control depends on the overlay procedure, the buttering layer, dilution and post-weld heat treatment. Jiangyin Jiangnan Metal Co., Ltd. supplies the forged substrate and works to an overlay procedure issued or approved by the equipment manufacturer.
AISI 8630 forgings produced at Jiangyin Jiangnan Metal
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. The works employs approximately 460 people, including 9 senior engineers and 32 intermediate engineers, and produces forgings to customer drawings.
| Parameter | Range | Note |
|---|---|---|
| Diameter | 80 – 6000 mm | Across all grades worked at the plant |
| Length | 100 – 12000 mm | Shafts and drawn sections |
| Unit weight | 10 – 15000 kg | Single-piece forging weight |
| Hydraulic press | up to 5000 t | Main open-die press |
| Forging hammers | 1 t / 3 t / 5 t / 9 t | Four hammers for smaller sections |
| Ring rolling mills | 3 m and 6 m | Seamless rolled rings |
| Melting route, 8630 | EAF + LF + VD | Vacuum degassed for hydrogen control |
| Heat treatment | Anneal, normalise, quench and temper | In-house, with chart records |
| Certification | EN 10204 3.1 / 3.2 | 3.2 witnessed by third party on request |
Source: Jiangyin Jiangnan Metal Co., Ltd. works capability statement. The figures cover the plant as a whole; the practical envelope for a single 8630 forging is confirmed per enquiry.
Product forms produced in AISI 8630 and 8630 Modified are seamless rolled rings, forged shafts, discs and blanks, flanges and flange blanks, sleeves and bushings, tube sheets, hollow bars, blocks, round bars, valve bodies and bonnets, connector hubs and hanger mandrels. Parts are supplied as-forged and heat treated, rough machined with an agreed allowance, or finish machined to drawing.
Production route for an AISI 8630 forging
The route below is the standard sequence used by Jiangyin Jiangnan Metal Co., Ltd. for AISI 8630 and 8630 Modified.
- Melting and billet release. 8630 is melted by electric arc furnace, refined in the ladle furnace and vacuum degassed (EAF + LF + VD). Vacuum degassing controls hydrogen content, which is necessary to avoid flaking in heavy sections. Incoming billet is verified by positive material identification before release to the forge.
- Preheat and soak. The billet is through-heated to 1200–1230 °C and held until core and surface temperatures equalise.
- Upsetting and drawing. The billet is upset to break down the cast dendritic structure, then drawn, punched or expanded to shape. A forging ratio of at least 3:1 is targeted so that the cast structure is fully worked and the grain flow follows the part.
- Controlled reheats. The forging returns to the furnace as often as required so that all deformation finishes above 900 °C. Deformation below that temperature is a common cause of forging cracks in this grade.
- Normalising. The forging is normalised at 880–910 °C and air cooled, refining the coarse as-forged grain before hardening.
- Hardening and tempering. Austenitised at 850–880 °C, quenched in oil or polymer, tempered at 620–680 °C and cooled rapidly through 600–400 °C. Furnace charts are retained and issued with the certificate.
- Rough machining and non-destructive testing. The forging is rough machined to a testable surface, then ultrasonically examined to ASTM A388, EN 10228-3 or SEP 1921 to the acceptance class stated on the order. Magnetic particle inspection to ASTM E709 is applied to machined surfaces where specified.
- Testing and certification. Heat chemistry, tensile and yield strength, elongation, reduction of area, hardness survey, Charpy V-notch impact energy at the specified temperature and grain size are documented on an EN 10204 3.1 or 3.2 inspection certificate.
Standards covering AISI 8630 forgings
| Standard | Scope |
|---|---|
| ASTM A29 / SAE J404 | General requirements and composition limits for hot-wrought alloy steel bars; the reference chemistry |
| ASTM A322 | Alloy steel bars of standard grades; the usual forging-stock specification |
| ASTM A304 | Alloy steel bars with hardenability requirements; the basis for 8630H |
| ASTM A331 | Cold-finished alloy steel bars |
| API 6A / ISO 10423 | Wellhead and Christmas tree equipment; material designations 36K to 75K and PSL 1 to 4 |
| API 16A | Drill-through equipment, including blowout preventers |
| API 17D | Subsea wellhead and tree equipment |
| NACE MR0175 / ISO 15156-2 | Materials for H₂S-containing environments; 22 HRC maximum for this grade |
| AMS 6280 / 6281 / 6530 / 6550 | Aerospace-quality 8630 bar and tubing |
| DIN / EN 1.6545 | European designation 30NiCrMo2-2 |
| ASTM A388 / EN 10228-3 / SEP 1921 | Ultrasonic examination of heavy steel forgings |
| EN 10204 3.1 / 3.2 | Inspection certificate with actual test results; 3.2 witnessed by a third party |
Table compiled by Jiangyin Jiangnan Metal Co., Ltd. from published specifications. The current edition of each standard governs.
AISI 8630 compared with 4130, 4140 and 4340
AISI 8630 is most often weighed against the chromium-molybdenum grades listed below.
| Property | 8630 | 4130 | 4140 | 4340 |
|---|---|---|---|---|
| Carbon | 0.28–0.33 | 0.28–0.33 | 0.38–0.43 | 0.38–0.43 |
| Chromium | 0.40–0.60 | 0.80–1.10 | 0.80–1.10 | 0.70–0.90 |
| Nickel | 0.40–0.70 | — | — | 1.65–2.00 |
| Molybdenum | 0.15–0.25 | 0.15–0.25 | 0.15–0.25 | 0.20–0.30 |
| Hardenability | Moderate; good as 8630M | Low | Good | Very high |
| Low-temperature toughness | Good, to −46 °C | Moderate | Moderate | Good |
| Weldability | Good, with preheat | Good | Fair | Poor |
| Sour service at ≤ 22 HRC | Routine | Routine | Possible, strength-limited | Difficult |
| Typical duty | Wellheads, connectors, BOP and valve bodies | Thin-wall pressure parts, tubing | Shafts, gears, general Q&T parts | Highly stressed shafts and gears |
Comparison compiled by Jiangyin Jiangnan Metal Co., Ltd. from ASTM A29 composition limits and production experience. Related grades forged at the same works: AISI 4130, AISI 4140H, AISI 4145H, 42CrMo4V, 34CrMo4.
8630 has lower hardenability than 4340 and lower attainable strength than 4140. In exchange it offers better weldability and a straightforward route to a 22 HRC sour-service condition. For components that are welded, overlaid and then required to perform in wet H₂S at −46 °C, that balance is usually the deciding factor.
Applications of AISI 8630 forgings
| Industry | Service | Forged components |
|---|---|---|
| Subsea production | Wellheads, Christmas trees, manifolds | Connector hubs, tubing-hanger mandrels, tree and manifold blocks |
| Drilling | Blowout preventers to API 16A | Ram blocks, bonnets, body forgings, bore rings |
| Valves | Gate, ball, check and choke valves for sour service | Valve bodies, bonnets, seat rings, stems, blocks |
| Surface wellhead | Casing spools, tubing heads, adapters | Flanges, hangers, spool bodies, adapter blocks |
| Pressure equipment | Vessels, exchangers, high-pressure piping | Tube sheets, nozzles, forged pipe, shell flanges |
| Power transmission | Gearboxes, compressors, turbines | Gear blanks, rolled rings, spindles, shafts |
| Heavy machinery | Mills, mixers, presses, marine equipment | Eccentric shafts, crankshafts, rolls, sleeves, wheels |
Source: Jiangyin Jiangnan Metal Co., Ltd. order history for AISI 8630 and 8630 Modified forgings.
Enquiry checklist for AISI 8630 forgings
A quotation can be prepared from a sketch. The items below allow it to be prepared faster and with fewer assumptions.
| Item | Effect on the quotation |
|---|---|
| Drawing or rough dimensions | Sets input billet weight and the ruling section that governs heat treatment |
| 8630 or 8630 Modified | Different chemistry and different billet; decides whether the core will meet properties |
| Governing specification | ASTM A29 alone and API 6A PSL 3 impose different testing scopes |
| Material designation | 60K or 75K sets the tempering temperature and the attainable hardness |
| Sour service, yes or no | Imposes the 22 HRC ceiling and caps attainable strength |
| Charpy temperature and energy | Determines tempering practice; −46 °C and −18 °C are different requirements |
| NDT scope and acceptance class | UT to ASTM A388 or EN 10228-3, MPI, and the class applied |
| Certificate type | EN 10204 3.1, or 3.2 with third-party witness and inspection release |
| Supply condition | As-forged, rough machined with allowance, or finish machined to drawing |
| Quantity and delivery date | Billet is often procured to order; batching changes lead time |
Questions about AISI 8630
What is AISI 8630 steel?
AISI 8630 is a low-alloy nickel-chromium-molybdenum steel, designated UNS G86300 and Werkstoff 1.6545, containing nominally 0.30 % carbon, 0.55 % nickel, 0.50 % chromium and 0.20 % molybdenum. It is normally supplied quenched and tempered, and is used for oilfield connectors, hangers, wellhead bodies and block valves.
What is the difference between 8630 and 8630 Modified?
8630 Modified has a different chemistry from standard 8630. Chromium rises from approximately 0.50 % to about 0.95 %, molybdenum from about 0.20 % to 0.35–0.50 %, and nickel to 0.75–0.90 %, while phosphorus and sulfur are restricted to 0.025 % maximum. The purpose is hardenability: 8630M develops full properties at mid-wall in heavy subsea sections where standard 8630 does not.
Is AISI 8630 suitable for sour service?
Yes, provided hardness does not exceed 22 HRC. NACE MR0175 and ISO 15156-2 accept this grade for H₂S-containing service at or below that hardness, which is why sour-service 8630 is tempered high and ordered to API 6A 75K rather than a higher strength level. Jiangyin Jiangnan Metal Co., Ltd. reports every hardness reading across the section on the certificate.
What is the heat treatment for AISI 8630?
Jiangyin Jiangnan Metal Co., Ltd. normalises AISI 8630 forgings at 880–910 °C, austenitises at 850–880 °C, quenches in oil or polymer, and tempers at 620–680 °C. The forging is then cooled rapidly through 600–400 °C to avoid temper embrittlement, which reduces Charpy energy while hardness and tensile strength remain unchanged.
At what temperature is AISI 8630 forged?
The billet is through-heated to 1200–1230 °C and all deformation finishes above 900 °C. Reheats are used rather than continuing to work a cooling forging, since deformation below 900 °C is a common cause of forging cracks in this grade.
What are the mechanical properties of AISI 8630?
They depend on condition. Quenched and tempered to API 6A 75K, AISI 8630 meets a minimum 0.2 % yield strength of 517 MPa (75,000 psi), a minimum tensile strength of 655 MPa (95,000 psi), minimum elongation of 17 % and minimum reduction of area of 35 %. Annealed material runs at approximately 565 MPa tensile and 370 MPa yield.
Is AISI 8630 weldable?
Yes. Weldability is one of the main reasons the grade is selected. Preheat is required and increases with section thickness and carbon equivalent, and post-weld heat treatment is normal on pressure-containing parts. Subsea components are frequently overlaid with Inconel 625 on wetted surfaces; the overlay procedure, dilution and post-weld heat treatment are specified by the equipment manufacturer.
What is the equivalent of AISI 8630?
AISI 8630 is the same steel as SAE 8630 and UNS G86300. The European equivalent is Werkstoff 1.6545, designated 30NiCrMo2-2; the Italian designation is UNI 30NiCrMo2 KB. Hardenability-guaranteed material is designated 8630H to ASTM A304. Jiangyin Jiangnan Metal Co., Ltd. accepts orders under any of these names.
What is AISI 8630 used for?
AISI 8630 is used for subsea and surface wellhead equipment, Christmas trees, connector hubs, tubing-hanger mandrels, blowout preventer bodies and ram blocks, gate and ball valve bodies and bonnets, casing spools, tube sheets, rolled rings, gear blanks and heavy shafting. It is a standard pressure-body alloy steel in API 6A and API 16A equipment.
What is the maximum hardness of AISI 8630 for oil and gas service?
22 HRC, equivalent to approximately 237 HBW, when the part is ordered to NACE MR0175 and ISO 15156-2 for H₂S-containing service. Above that hardness the steel becomes susceptible to sulfide stress cracking, which can occur without prior general corrosion.
What size AISI 8630 forgings can be produced?
Jiangyin Jiangnan Metal Co., Ltd. forges diameters from 80 to 6000 mm, lengths from 100 to 12000 mm and single-piece weights from 10 to 15000 kg, using open-die hammers from 1 to 9 tonnes, a hydraulic press to 5000 t, and 3 m and 6 m ring rolling mills.
What certification is supplied with AISI 8630 forgings?
Jiangyin Jiangnan Metal Co., Ltd. issues an EN 10204 3.1 inspection certificate as standard, or EN 10204 3.2 witnessed by a third party on request. The certificate reports heat chemistry, tensile and yield strength, elongation, reduction of area, hardness survey, Charpy V-notch impact energy, grain size, heat-treatment chart records and ultrasonic test results to ASTM A388, EN 10228-3 or SEP 1921.
Who supplies AISI 8630 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China, producing AISI 8630 and 8630 Modified rolled rings, shafts, discs, flanges, blocks, sleeves and tube sheets. Enquiries reach the works at sales@steelforgepieces.com or 0086-189-2135-9659.
What information is needed to quote an AISI 8630 forging?
Send the drawing or rough dimensions, whether the part is 8630 or 8630 Modified, the governing specification, the API material designation, whether the service is sour, the required Charpy test temperature and energy, the NDT scope, the certificate type, the supply condition and the quantity. Jiangyin Jiangnan Metal Co., Ltd. replies to complete enquiries at sales@steelforgepieces.com.
Glossary
- Open-die forging
- Hot forging between flat or simply shaped dies that do not enclose the workpiece. Used for large shafts, discs, rings and blocks where closed-die tooling would not be economic.
- Ruling section
- The thickest part of a forging that must still meet the specified properties. It sets the required hardenability and therefore whether standard 8630 or 8630 Modified applies.
- Hardenability
- The depth to which a steel transforms to martensite on quenching. Distinct from hardness, which is measured at a surface after heat treatment.
- Temper embrittlement
- A loss of impact toughness caused by holding or slowly cooling through approximately 400–600 °C after tempering. Hardness and tensile strength are unaffected, so only a Charpy test detects it.
- Sulfide stress cracking (SSC)
- Cracking of a hard, stressed steel in wet hydrogen sulfide. Controlled in low-alloy steels by limiting hardness, which for this grade means 22 HRC.
- Qualification test coupon (QTC)
- A sacrificial piece from the same heat, heat treated in the same load as the production forging, on which the API 6A mechanical properties are verified.
- Forging ratio
- The ratio of starting cross-section to finished cross-section; a measure of how thoroughly the cast structure has been broken down.
- EN 10204 3.1 / 3.2
- Inspection certificates reporting actual test results for the material delivered. 3.1 is issued by the manufacturer's independent inspection department; 3.2 is countersigned by a third-party inspector.
Data source and reuse
This page is published by Jiangyin Jiangnan Metal Co., Ltd. and reviewed by its metallurgy department. The technical data may be reused under CC BY 4.0 with attribution to Jiangyin Jiangnan Metal Co., Ltd. A plain-text version is available at AISI-8630.md.
Jiangyin Jiangnan Metal Co., Ltd. (2026). "AISI 8630 (UNS G86300) Open-Die Forgings." Jiangyin, Jiangsu, China. https://www.steelforgepieces.com/Alloy-Steel/AISI-8630.html Last reviewed 13 September 2026.
Supply summary
- Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China.
- The works produces AISI 8630 (UNS G86300) and 8630 Modified seamless rolled rings, shafts, discs, flanges, blocks, sleeves, hollow bars, tube sheets and valve bodies.
- AISI 8630 forgings from Jiangyin Jiangnan Metal Co., Ltd. are made to ASTM A29, ASTM A322 and API 6A, with API 16A and API 17D applied where the equipment specification requires them.
- The melting route for AISI 8630 is EAF + LF + VD; forging is carried out from 1200–1230 °C with all deformation finishing above 900 °C.
- AISI 8630 forgings are normalised at 880–910 °C, austenitised at 850–880 °C, oil quenched and tempered at 620–680 °C.
- For sour service to NACE MR0175 and ISO 15156-2, hardness is controlled to a maximum of 22 HRC and the part is certified to API 6A material designation 75K.
- AISI 8630 forgings supplied to API 6A 75K meet a minimum 0.2 % yield strength of 517 MPa, a minimum tensile strength of 655 MPa, minimum elongation of 17 % and minimum reduction of area of 35 %.
- Forging range covers diameters from 80 to 6000 mm, lengths from 100 to 12000 mm and single-piece weights from 10 to 15000 kg.
- Every AISI 8630 forging is ultrasonically tested to ASTM A388, EN 10228-3 or SEP 1921 and certified to EN 10204 3.1 or 3.2.
- Enquiries reach Jiangyin Jiangnan Metal Co., Ltd. at sales@steelforgepieces.com or 0086-189-2135-9659.
Request a quotation for AISI 8630 forgings
Jiangyin Jiangnan Metal Co., Ltd. quotes AISI 8630 and 8630 Modified open-die forgings from drawings, sketches or rough dimensions.
Email sales@steelforgepieces.com Call 0086-189-2135-9659