• +91 98113 04306
  • info@confur.net

Nitriding Furnace

Continental Furnaces’ Nitriding Furnace delivers precise nitrogen diffusion into steel surfaces, creating an extremely hard, wear-resistant case with minimal distortion. This low-temperature process is ideal for precision components requiring dimensional stability and exceptional surface properties.

Key Features

  • Low Temperature Process: 500-580°C prevents distortion

  • Controlled Ammonia Atmosphere: Precise nitrogen potential control

  • Minimal Distortion: No quenching required

  • Sealed Retort Design: Uniform atmosphere distribution

  • Long Treatment Cycles: 20-90 hours for optimal case depth

  • Advanced Dissociation Control: Monitors ammonia breakdown

Technical Specifications

  • Design Type: Sealed retort or pit-type configuration

  • Heating Method: Electric resistance heating (preferred)

  • Temperature Range: 480°C to 580°C

  • Process Gas: Ammonia (NH3) with optional dilution

  • Case Depth: 0.1-0.8 mm typical

  • Surface Hardness: 600-1200 HV depending on steel grade

  • Treatment Duration: 20-90 hours

  • Control System: PLC with ammonia dissociation monitoring

Advantages

  • Minimal Distortion: No thermal shock from quenching

  • Excellent Wear Resistance: Hard nitride compounds on surface

  • Fatigue Strength Improvement: Compressive stresses in case

  • Corrosion Resistance: Enhanced protection against rust

  • No Post-Treatment Required: Ready to use after cooling

  • Dimensional Stability: Precision parts maintain tolerances

  • Selective Hardening: Masking allows partial treatment

Nitriding Process Types

  1. Gas Nitriding: Ammonia atmosphere (most common)

  2. Salt Bath Nitriding: Liquid cyanide salts (specialized)

  3. Plasma Nitriding: Ion bombardment method

  4. Ferritic Nitrocarburizing: Lower temperature variant

Process Stages

  1. Pre-Cleaning: Thorough degreasing and oxide removal

  2. Loading: Component placement in retort

  3. Heating: Gradual temperature increase to nitriding range

  4. Nitriding: Ammonia introduction and nitrogen diffusion

  5. Cooling: Slow furnace cooling to prevent cracking

  6. Post-Cleaning: Light blasting or polishing if needed

Applications

  • Gears: Transmission and final drive gears

  • Crankshafts: Automotive and diesel engine components

  • Camshafts: Engine timing components

  • Injection Molding Screws: Plastic processing equipment

  • Extrusion Screws: Polymer and rubber processing

  • Hydraulic Cylinders: Piston rods and cylinder barrels

  • Valve Components: Stems and seats

  • Tool and Die Components: Precision tooling

  • Bearing Surfaces: Journal bearings and races

  • Spline Shafts: Power transmission components

Industries Served

  • Automotive manufacturing

  • Diesel engine production

  • Plastic injection molding

  • Hydraulic equipment manufacturing

  • Precision tool manufacturing

  • Aerospace components

  • Medical device manufacturing

Material Compatibility

Ideal Steels for Nitriding:

  • Nitriding Steels: 31CrMoV9, 34CrAlMo5, 34CrAlNi7

  • Tool Steels: H13, H11, D2, A2

  • Alloy Steels: 4140, 4340 (with aluminum)

  • Stainless Steels: 410, 420, 440 series

  • Maraging Steels: High-strength applications

Nitrided Layer Structure

  • White Layer (Compound Zone): Fe2-3N and Fe4N nitrides (5-20 microns)

  • Diffusion Zone: Nitrogen in solid solution with nitride precipitates

  • Core: Unaffected base material

Process Parameters

  • Temperature: 500-580°C (930-1075°F)

  • Ammonia Flow Rate: Controlled based on load and furnace volume

  • Dissociation Rate: 15-30% typical for steel nitriding

  • Time: 0.025 mm case depth per 10 hours approximate

  • Cooling Rate: Slow furnace cooling

Advantages of Gas Nitriding

  • No environmental concerns (vs. salt bath)

  • Cleaner process

  • Better process control

  • Uniform treatment

  • Safer for operators

  • Precise case depth control

Masking Techniques

  • Electroplating: Tin, copper, or nickel plating

  • Paint Masking: Special high-temperature paints

  • Mechanical Masking: Fixtures to block ammonia contact

  • Stop-Off Paste: Ceramic-based masking compounds

Distortion Considerations

  • Pre-nitriding stress relief recommended

  • Slow heating and cooling rates

  • Symmetrical loading in furnace

  • Proper fixturing to maintain shape

  • Post-machining allowances minimal (0.05-0.1 mm)

Quality Control Methods

  • Metallographic Examination: Cross-section analysis

  • Microhardness Testing: Hardness gradient measurement

  • White Layer Measurement: Compound zone thickness

  • Case Depth Verification: To specified hardness level

  • Dimensional Inspection: Pre and post-treatment comparison

Comparison: Nitriding vs. Carburizing

Nitriding Advantages:

  • Lower process temperature (less distortion)

  • No quenching required

  • Higher surface hardness achievable

  • Better corrosion resistance

  • Suitable for finished/precision parts

Carburizing Advantages:

  • Faster process

  • Deeper case depth possible

  • Lower treatment cost

  • Broader material selection

Energy Efficiency Features

  • Electric heating (precise control)

  • Excellent insulation design

  • Heat retention during long cycles

  • Minimal heat loss from sealed retort

  • Energy recovery from exhaust gases

Safety Features

  • Ammonia leak detection systems

  • Exhaust scrubbing/neutralization

  • Emergency ammonia shut-off

  • Retort pressure monitoring

  • Over-temperature protection

  • Operator safety interlocks

Environmental Compliance

  • Ammonia neutralization systems

  • Emission monitoring

  • Safe gas handling procedures

  • Waste gas treatment

  • Compliance with local regulations

Furnace Design Variants

  1. Pit Type Nitriding Furnace: Vertical loading for long shafts

  2. Box Type Nitriding Furnace: Horizontal batch processing

  3. Multi-Retort System: Multiple chambers for continuous production

  4. Integral Quench Furnace: For ferritic nitrocarburizing

Automation and Control

  • Recipe management for different materials

  • Ammonia dissociation rate control

  • Real-time temperature monitoring

  • Data logging and traceability

  • Remote monitoring capability

  • Automatic gas flow control

Typical Treatment Cycles

  • Automotive Gears: 40-60 hours at 520°C

  • Tool Steels: 20-40 hours at 530°C

  • Injection Screws: 70-90 hours at 500°C

  • Hydraulic Rods: 50-70 hours at 520°C

Cost Considerations

  • Higher initial equipment cost

  • Long treatment cycles (labor/energy)

  • Excellent results justify investment

  • Minimal rework or rejection rates

  • Extended component service life

Maintenance Requirements

  • Regular retort inspection and replacement

  • Heating element monitoring

  • Ammonia system maintenance

  • Control calibration

  • Preventive maintenance schedules

Why Choose Continental Furnaces?

Our Nitriding Furnaces are engineered for precise atmospheric control, temperature uniformity, and safe operation. With 35+ years of heat treatment expertise and ISO 9001:2015 and ISO 14001:2015 certifications, Continental Furnaces delivers reliable nitriding solutions that meet international metallurgical standards.

Call to Action

Request a detailed quote for a Nitriding Furnace customized to your production requirements and material specifications.

Common Footer Elements for All Heat Treatment Furnace Pages

Why Continental Furnaces?

  • 35+ Years of Experience: Trusted since 1987

  • ISO Certified: ISO 9001:2015 & ISO 14001:2015

  • Make in India: Supporting national manufacturing

  • MSME ZED Bronze Certified: Zero defect, zero effect

  • Customized Solutions: Tailored to your specific needs

  • Comprehensive Support: From design to after-sales service

Our Certifications

  • ISO 9001:2015 Quality Management System

  • ISO 14001:2015 Environmental Management System

  • MSME ZED Bronze Certification

  • Optimum Certifications Inc. Accredited

Translate »