Ni-Hard Castings
Welcome to Bhanu Special Castings Pvt. Ltd. - your trusted partner for ultra-hard Ni-Hard castings in Vijayawada and across India. As a specialized white cast iron foundry, we manufacture Ni-Hard alloys containing 4-5% nickel and 1.5-3% chromium, delivering extreme wear resistance with superior toughness compared to standard white iron—ideal for crusher liners, slurry pump impellers, grinding mill components, and cement kiln applications requiring both abrasion and impact resistance.
Ni-Hard castings are martensitic white cast irons where nickel addition (4-5%) provides toughness and impact resistance while chromium (1.5-3%) forms massive carbides for hardness (550-700 HB). Unlike brittle standard white iron, Ni-Hard combines extreme hardness with 2-3x better impact resistance, making it the preferred choice for abrasive-erosive wear where both sliding abrasion and moderate impact occur simultaneously—such as slurry pumps handling mineral concentrates, crusher mantles in secondary/tertiary crushing, and cement mill liners.
Our Ni-Hard castings deliver exceptional performance including extreme hardness (550-700 HB depending on grade), outstanding abrasion-erosion resistance in slurries, superior impact toughness vs. white iron, good corrosion resistance in acidic slurries, and weldability with proper procedures. Manufactured to ASTM A532 Class III Type D, Ni-Hard 1, 2, 4 standards, these castings serve as slurry pump impellers and volutes, crusher mantles and concaves, grinding mill liners, dredge pump components, and cement kiln riding rings. With advanced heat treatment and comprehensive hardness testing, every casting meets the demanding requirements of mining, dredging, and mineral processing industries.
Our Product Range
We manufacture ultra-hard Ni-Hard castings engineered for severe abrasive and erosive wear with impact:
- Slurry Pump Components Impellers, volutes, throat bushes, and suction liners for abrasive slurries.
- Crusher Liners Mantles, concaves, bowl liners, and adjustment rings for high-wear crushing zones.
- Grinding Mill Parts Shell liners, end liners, and lifter bars for abrasive grinding applications.
- Dredge Pump Components Impellers, cutters, wear plates, and suction pipes for dredging operations.
- Cyclone Components Apex cones, feed chambers, and vortex finders for classification systems.
- Cement Kiln Parts Riding rings, trunnions, and roller segments for abrasive kiln environments.
- Mining Equipment Wear Parts Chute liners, discharge spouts, and apron feeder components.
- Custom Ni-Hard Castings Application-specific designs manufactured to customer requirements.
Weight Range: 1 kg to 5000 kg | Hardness: 550–700 HB
Industry Applications
Our Ni-Hard castings serve extreme abrasive and erosive wear applications across:
- Mining & Mineral Processing Ore slurry pumping, grinding, and classification systems.
- Dredging Operations Sand and gravel pumping, seabed mining, and channel deepening.
- Cement Manufacturing Raw material grinding, clinker handling, and kiln operations.
- Coal Handling Ash slurry pumps, coal washing plants, and FGD systems.
- Aggregate Processing Secondary and tertiary crushing, sand and aggregate production.
- FGD Systems Flue gas desulfurization pumps, agitators, and slurry handling equipment.
- Tailings Handling Cyclones, slurry pumps, and tailings pipelines.
- Chemical Processing Abrasive slurry transfer and neutralization systems.
Ni-Hard castings are martensitic white cast irons containing 4-5% nickel and 1.5-3% chromium with 2.5-3.5% carbon, creating a unique microstructure of chromium-iron carbides in a tough nickel-enriched martensitic matrix. The nickel provides exceptional impact toughness (2-3x better than standard white iron) while chromium carbides deliver extreme hardness (550-700 HB)—making Ni-Hard the optimal choice for slurry pumps, dredge equipment, and crusher components where combined abrasion-erosion-impact wear occurs simultaneously in aggressive mineral slurries.
Ni-Hard Manufacturing & Heat Treatment Process
Our Ni-Hard foundry employs precise nickel-chromium control with controlled cooling and heat treatment to produce white cast iron with optimal carbide distribution and martensitic toughness.
Alloy Melting
Precise Ni (4-5%), Cr (1.5-3%), C (2.5-3.5%) control, electric induction furnace, spectroscopic verification.
Casting & Cooling
Controlled cooling rate (critical for martensite formation), air cooling for Ni-Hard 1/2, oil quench for Ni-Hard 4.
Stress Relief
250-350°C stress relieving to reduce cracking risk, slow cooling, maintaining hardness at 550-700 HB.
| Ni-Hard Grade | Ni % | Cr % | Hardness (HB) | Best Applications |
|---|---|---|---|---|
| Ni-Hard 1 | 4.0-5.0 | 1.4-4.0 | 550-650 | Slurry pump impellers, dredge cutters (best toughness) |
| Ni-Hard 2 | 4.5-5.5 | 2.0-3.0 | 600-700 | Crusher mantles, cyclone liners (higher hardness) |
| Ni-Hard 4 | 5.0-7.0 | 7.0-11.0 | 650-750 | Corrosive slurries, FGD pumps (maximum Cr for corrosion) |
Key Properties & Benefits of Ni-Hard Castings
Ni-Hard castings combine the extreme hardness of white iron with the improved toughness of a nickel-enriched martensitic matrix. This unique structure delivers an optimal balance of abrasion resistance and impact strength, making Ni-Hard ideal for severe slurry and erosive wear applications.
- Extreme Hardness Hardness levels typically range from 550–700 HB depending on grade: Ni-Hard 1 (550–650 HB), Ni-Hard 2 (600–700 HB), and Ni-Hard 4 (650–750 HB).
- Superior Toughness Provides 2–3 times better impact resistance than conventional white iron or high-chrome iron, as the nickel-enriched martensitic matrix effectively absorbs shock.
- Excellent Abrasion–Erosion Resistance Ideal for slurry pumps where particles cause combined sliding, impact, and erosive wear. Delivers 3–5 times longer service life than rubber liners in high-concentration slurries.
- Good Corrosion Resistance Performs well in acidic slurry environments with pH values between 3 and 9. Ni-Hard 4, containing 7–11% chromium, is particularly effective for FGD applications.
- Improved Weldability Can be hardfaced and repaired using proper preheating procedures and high-nickel electrodes, offering better weldability than high-chrome irons.
- Cost-Effective Wear Solution More economical than duplex stainless steels or ceramic-lined systems, with typical impeller service life of 2–3 years in copper and iron ore concentrate applications.
Customization and Quality Assurance
We provide fully customized Ni-Hard castings engineered for your specific slurry conditions, from nickel-chromium content selection (Ni-Hard 1, 2, or 4) and geometry optimization to heat treatment for maximum impeller/liner life. Our team in Vijayawada ensures every component delivers optimal wear resistance in your abrasive-erosive application.
Customization Capabilities
- Grade selection (Ni-Hard 1 for toughness, Ni-Hard 4 for corrosion)
- Slurry pump impeller design optimization (vane angles, clearances)
- Crusher liner geometry for cone/gyratory crushers
- Pattern-less casting for urgent replacement parts
- Hardfacing/overlay for extended life in critical zones
- OEM replacement parts (Warman, Metso, Weir, Flowserve)
Quality Testing & Certifications
- Chemical Analysis Verification of nickel, chromium, carbon, and manganese content in accordance with ASTM A532 requirements.
- Hardness Testing Brinell hardness mapping performed to confirm hardness range between 550–700 HB across critical wear zones.
- Microstructure Examination Metallographic analysis to verify carbide distribution and martensitic matrix structure.
- Dimensional Inspection Precision inspection of critical dimensions and fits for slurry pump and wear-part assemblies.
- Impact Testing Charpy or Izod impact testing conducted for Ni-Hard Grade 1 to assess impact resistance.
- ASTM A532 Class III Compliance Full material certification and traceability provided in accordance with ASTM A532 Class III standards.
Every Ni-Hard casting undergoes rigorous testing including spectroscopic Ni/Cr analysis, hardness verification at multiple locations, microstructure examination for martensite/carbide balance, and dimensional inspection. Our quality protocol guarantees compliance with ASTM A532 Class III Type D standards.
Why Choose Bhanu Special Castings for Ni-Hard?
With specialized expertise in Ni-Hard slurry pump and crusher components for mining, dredging, and mineral processing, we deliver consistent toughness, optimal wear life, and emergency replacement capability. Here's why we're trusted:
Slurry Pump Specialists
Decades supplying Ni-Hard impellers, volutes, liners for mining concentrator pumps; 2-3 year service life typical.
Dredging Industry Leader
Trusted supplier for dredge pump impellers, cutters, wear plates—superior toughness vs. white iron prevents catastrophic failure.
Metallurgical Expertise
In-house lab verifies martensite formation, carbide distribution—ensuring consistent 550-700 HB with maximum toughness.
OEM Replacement Parts
Manufacture direct replacements for Warman, Metso, Weir, Flowserve pumps/crushers—identical dimensions, superior wear life.
Emergency Supply
Fast-track casting for critical pump/crusher failures minimizing concentrator downtime—4-6 week emergency delivery.
Application Engineering
Wear analysis, grade selection guidance (Ni-Hard 1 vs. 4), design optimization for your specific slurry conditions.
Grades and Applications of Ni-hard Castings
Our Ni-hard castings are manufactured in multiple grades to suit demanding industrial applications. Common grades include EN 1.4526 (Ni-hard 1), EN 1.4534 (Ni-hard 2), EN 1.4542 (Ni-hard 4), EN 1.4418 (Ni-hard 5) , and EN 1.4678 (Ni-hard 6), all designed for exceptional hardness, toughness, and abrasion resistance.
Due to their extreme wear resistance, Ni-hard castings are widely used in industries where high abrasion and impact are encountered. Key application areas include:
- Mining & Mineral Processing: Heat-resistant components for furnaces, kilns, and smelting operations.
- Cement Production: High-strength castings for rotary kilns, clinker coolers, and dust collectors.
- Power Generation: Boiler tube shields, turbine components, and heat exchangers.
- Dredging Equipment: Durable wear plates, suction pipes, and drag heads for long service life.
- Industrial Pumps: Custom-cast impellers, shafts, and casings for extreme working conditions.
- Crusher Wear Parts: Breaker plates, hammer tips, and side liners for high impact resistance.
- Grinding Equipment: Precision-cast rollers, mill rings, and classifier parts for improved efficiency.
- Heavy-duty Valves & Components: Gate valves, seat rings, and stems designed for corrosive environments.
Typical Composition & Properties (Common Ni-Hard Grades – ASTM A532 Class I / EN Equivalents)
| Element / Property | Typical Range / Value | Notes (Ni-Hard 1/2/4; As-Cast or Heat-Treated) |
|---|---|---|
| Carbon (C) | 2.4–3.6% | Higher C increases hardness/abrasion; lower for better toughness (e.g., Ni-Hard 2) |
| Nickel (Ni) | 3.0–7.0% | Key for hardenability/matrix toughness; 3–5% in Ni-Hard 1/2, 4.5–7% in Ni-Hard 4 |
| Chromium (Cr) | 1.4–11.0% | Forms carbides for wear; 1.4–4% in Ni-Hard 1/2, 7–11% in Ni-Hard 4 |
| Silicon (Si) | 0.8–2.0% | Controls fluidity; higher in some grades |
| Manganese (Mn) | ≤2.0% | Strengthens matrix |
| Hardness (Brinell) | 500–700+ HB | Ni-Hard 1/2: 550–650 HB; Ni-Hard 4: 600–700+ HB; exceptional abrasion resistance |
| Tensile Strength | 300–500 MPa | Low due to brittleness; compressive strength much higher |
| Abrasion Resistance | Very High | Excellent in gouging/sliding wear; 60–80x better than mild steel in erosive tests |
Values typical for ASTM A532 Class I (Ni-Hard 1/2/4) and EN equivalents; hardness/abrasion vary with section size/heat treatment. Custom adjustments available for specific wear needs.
Frequently Asked Questions (FAQ)
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