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Stellite 6 Round Bars Supplier in Mumbai, India – UNS R30006
Nicorex Alloys is an ISO 9001/ISO 14001-certified supplier, stockist, and trading company of Stellite 6 Round Bars based in Mumbai, India. We supply batch-tested Stellite Grade 6 round bars with full compliance to AWS A5.21 (ERCoCr-A), AMS 5788, AMS 5894 and ISO 14700. Ready stock is available for both domestic and international delivery.
Stellite Grade 6, also called Cobalt Alloy 6, is a widely used hardfacing alloy made of cobalt, chromium, and tungsten that helps protect against wear and tear. Its microstructure consists of chromium-rich M₇C₃ carbides dispersed in a CoCr solid-solution matrix. This structure, which consists of carbide embedded in a matrix, is resistant to abrasion, erosion, galling, and cavitation in a single alloy. It maintains a reliable level of toughness up to 500°C (930° Fahrenheit). Valve seats and gates, pump shafts and bearings, erosion shields, rolling pairs, and components for steam turbines are all potential applications for round bar products.
It is an alloy based on cobalt, containing 29% chromium, 4.5% tungsten, and 1.2% carbon. Stellite 6 round bars are known for their hardness, ranging from 36 to 45 HRC, as well as their density, which is 8.44 g/cm³, and are non-magnetic. It also shows superior resistance to abrasion and cavitation, as well as galling. We supply this grade in 5 mm to 300 mm diameters, offered in cast or wrought finishes. The material’s structural integrity ensures excellent performance during turning operations using standard carbide tooling. It also shows integrity up to a temperature range of 1250°C to 1360°C
Nicorex Alloys also supplies Stellite alloy grade 6 plates and sheets. Precision-engineered Stellite 6 round bars offer superior galling resistance and are available with full EN 10204/3.1 certification to meet stringent global engineering standards
Cobalt Alloy UNS R30006 Bar Specifications
Following is the table providing details of the specification, including AWS, diameter, length, conditions, certifications and other required information for Cobalt Alloy UNS R30006 Bar
| AWS | A5.21 ERCoCr-A (rod), ERCCoCr-A (wire); A5.13 ECoCr-A (electrode) |
|---|---|
| AMS | AMS 5387 / AMS 5373 (castings); AMS 5788 (rod/wire); AMS 7239 (P/M); AMS 5894 (wrought 6B) |
| Diameter | 5 mm to 300 mm (wrought 6B: up to 152 mm / 6”) |
| Length | 300 mm to 3000 mm (wrought 6B: up to 4064 mm / 160”) |
| Manufacturing | Casting (investment, centrifugal, sand), HIP, P/M, Wrought (6B) |
| Conditions | As-Cast, HIPed, Wrought (6B), Ground, Centreless Ground |
| Tolerances | Standard or h6/h7 (ground bars) |
| Testing | PMI, Hardness (HRC), Chemical Analysis, UT, Dimensional |
| Certification | MTC per EN 10204 – 3.1 / 3.2 |
Chemical Composition of Stellite 6 Alloy
The following table gives the composition of Stellite 6 according to A5.13 specifications, highlighting the vital elements of the cobalt-chromium-tungsten alloy
| Element | Cobalt (Co) | Chromium (Cr) | Tungsten (W) | Carbon (C) | Nickel (Ni) | Iron (Fe) | Silicon (Si) | Molybdenum (Mo) |
|---|---|---|---|---|---|---|---|---|
| Min | Balance (~55–65) | 27.0 | 3.0 | 0.9 | – | – | – | – |
| Max | Balance (~55–65) | 32.0 | 6.0 | 1.4 | 3.0 | 3.0 | 1.5 | 1.0 |
Chromium forms M₇C₃ carbides and a Cr₂O₃ layer for wear and oxidation protection up to 800°C. Tungsten strengthens the cobalt matrix’s hot hardness, while Carbon (0.9–1.4%) balances toughness with wear resistance. Cobalt provides essential galling resistance
Mechanical Properties of Stellite 6 Bar and Rod
Refer to the following table for the mechanical properties of Stellite 6 bar and rod, detailing strength and hardness metrics.
| Property | Hardness | UTS (typical) | Yield (typical) | Elongation | Density | Elastic Modulus |
|---|---|---|---|---|---|---|
| Value | HRC 36–45 (380–490 HV) | 793–896 MPa (115–130 ksi) | 541–662 MPa (78–96 ksi) | 1–3% | 8.44 g/cm³ (0.305 lb/in³) | ~209 GPa |
Wrought Stellite 6B (UNS R30016, AMS 5894) offers 4x the Charpy impact toughness of cast Stellite 6 and provides improved fatigue resistance. Carbide tooling turns cobalt alloy grade 6, unlike Stellite 1, 12, or 3.
Physical Properties of Cobalt Alloy 6
This table lists the physical properties of Stellite Grade 6 (UNS R30006), including its density and thermal properties.
| Property | Density | Melting Range | Thermal Expansion (20–500°C) | Thermal Conductivity (25°C) | Magnetic Behaviour |
|---|---|---|---|---|---|
| Value | 8.44 g/cm³ (0.305 lb/in³) | 1250–1360°C (2282–2480°F) | ~14.4 µm/m·°C | ~14.8 W/m·K | Non-magnetic (paramagnetic) |
Despite cobalt’s ferromagnetic nature, it remains non-magnetic. Cr and W alloying suppresses ferromagnetic behaviour.
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Available Types of Stellite Grade 1 Round Bar
Nicorex Alloys stocks and supplies Stellite Grade 1 round bars in the following forms:
Stellite 6 Cast Round Bar
Stellite 6B Wrought Round Bar
UNS R30006 Ground Bar
Cobalt Alloy Grade 6 Ground Bar
UNS R30006 Centreless-Ground Bar
Stellite 6 Alloy Rod
Wear Resistance & Corrosion Behaviour of Stellite Alloy 6
Stellite Grade 6 is the most versatile wear-resistant cobalt alloy. M7C3 carbides in the CoCr matrix resist abrasion, erosion, galling, and cavitation in a single alloy.
Cavitation erosion resistance is significantly better than that of Stellite 1. Impact toughness far exceeds higher-carbon grades, making cobalt alloy 6 suitable for repeated mechanical or thermal shock.
Good corrosion resistance comes from 27–32% chromium. In seawater, this material holds an electrical potential of about –0.25 V, meaning it resists general rusting but can develop tiny pits. At 22°C, the metal wears away incredibly slowly, less than 0.05 mm each year. Additionally, it stays protected from heat damage up to 800°C thanks to a thin, tough chromium oxide layer that acts like a shield.
Galling resistance is excellent. Low friction allows self-mating (Stellite 6 vs Stellite 6) for valve seats, pump bearings, and rolling couples.
Limitations: Not suited for severe hard-particle abrasion (use Stellite 1 or 12). Hot hardness retention is limited to ~500°C vs 760°C for Stellite 1.
Industries & Applications of Stellite 6 Round Bar
The following are the industries where Stellite 6 Round Bar is applicable:
- Valve seats and gates in choke, gate, and ball valves. Pump shafts and bearing sleeves. MWD tool components.
- Steam turbine erosion shields (the largest application for Stellite 6B wrought bar). Valve trim for steam service up to 500°C. Boiler feed pump wear rings.
- Bearing surfaces per AMS 5894. Turbine blade erosion protection. One of the few cobalt alloys carrying multiple AMS specifications for aerospace use.
- Valve seats and plug valves in corrosive environments. Agitator shafts and seal rings.
- Stellite 6B for food processing blades. It is non-magnetic, corrosion-resistant, and non-toxic for food-contact service.
- Trimming main and secondary valves. Under neutron radiation, cobalt becomes Co-60 (BWR issue). PWR secondary systems freely employ Stellite 6. Some operators provide cobalt-free options.
How to Order Stellite Grade 6 Round Bar from Nicorex Alloys
Please provide the following 13 details to place an order for Stellite Grade 6 Round Bar from Nicorex Alloys
- Alloy Grade: Stellite Grade 6 / UNS R30006 (or Stellite 6B / UNS R30016 for wrought)
- Product Form: Round bar, rod, cast bar, wrought bar (6B)
- Diameter (mm or inches)
- Length (standard or custom)
- Quantity (kg, pieces, or MT)
- Surface Finish: As-cast, rough-turned, precision-ground, centreless-ground, polished
- Specification: AMS 5387/5373 (castings), AMS 5788 (rod), AMS 5894 (wrought 6B), or customer spec
- Testing: Hardness (HRC), chemical analysis, PMI, UT, dimensional
- Delivery: Domestic India / internation specify the details of address
Frequently Asked Questions
What is the Price of Stellite 6 Round Bar in India?
The price of Stellite 6 Round Bar in India varies depending on its diameter, condition (cast vs. wrought 6B), specifications, and the current cobalt market rates. Wrought 6B is valued at a markup over cast forms, reflecting its superior mechanical properties. Contact Nicorex Alloys for current pricing.
What is the Hardness of Cobalt 6 Alloy Round Bar?
Cast or HIPed materials exhibit hardness between HRC 36 and 45. The hardness of the Cobalt 6 alloy round bar is moderate compared to Stellite 1 (HRC 50–58), but it offers superior impact toughness and machinability.
Can Stellite Grade 6 be Machined?
Yes. Carbide tooling works, though grinding remains preferred. Wire EDM and sinker EDM are also feasible. Stellite.
What is the Maximum Service Temperature for Stellite Grade 6?
The material maintains its hardness up to 500°C (930°F).
What is the Difference between Stellite Grade 6 and Stellite Grade 1?
While Grade 6 features a carbon content of 0.9–1.4% and 3–6% tungsten for a hardness of 36–45 HRC, Grade 1 utilises a higher 2.0–3.0% carbon and 11–13% tungsten range to achieve 50–58 HRC. Grade 6 has better toughness, machinability, and cavitation resistance. Grade 1 is for severe abrasion and hot service above 760°C, but is brittle.
What is the Difference between Stellite 6 and Stellite 6B?
While sharing the same chemistry, Stellite 6 is cast, whereas 6B (R30016/AMS 5894) is a wrought version. Wrought 6B delivers 4× Charpy impact toughness and better fatigue resistance. It is specified for aerospace bearings and turbine erosion shields.
Is Stellite 6 Magnetic?
Stellite 6 is strictly non-magnetic (paramagnetic), as its cobalt-chromium base lacks a ferromagnetic response. Cr and W additions suppress cobalt’s natural ferromagnetism.
What Welding Processes Work with Stellite 6 Alloy?
This material supports OAW, GTAW, GMAW, SMAW, PTA, HVOF, and laser cladding using AWS A5.21 rod/wire or A5.13 electrodes.
Is Stellite Grade 6 Suitable for Nuclear Applications?
Yes, with caveats. It is widely used for valve trim. Cobalt activates to Co-60 under neutron flux (BWR concern). PWR secondary systems use it freely.