The Road Milling Machine Drum Housing is the structural enclosure that supports the rotating cutting drum on cold planers and road milling machines. Subjected to extreme vibration, impact loads from cutting tools engaging asphalt at 2–3 m/min, and abrasive dust environments, this housing demands exceptional mechanical properties and structural rigidity. Ningbo Ruican manufactures this component using QT600-3 ductile iron through sand casting, delivering the complex housing geometry, bearing seat precision, and vibration damping characteristics that road construction equipment OEMs require. The integrated CNC machining process ensures bearing bore concentricity within 0.02mm, critical for drum rotation stability and cutting depth accuracy.
Material Specifications
| Parameter | Specification |
|---|---|
| Material Grade | QT600-3 (Ductile Iron / Nodular Cast Iron) |
| Tensile Strength | ≥ 600 MPa |
| Yield Strength (0.2%) | ≥ 370 MPa |
| Elongation | ≥ 3% |
| Hardness | 190–270 HB |
| Heat Treatment | Normalizing at 900°C |
| Wall Thickness | 8–22 mm |
| Dimensional Tolerance | CT7 (ISO 8062) |
| Weight Range | 12.0–55.0 kg |
Manufacturing Process
- Wax Pattern Injection: Large-format wax injection die for drum housing geometry (up to 600mm length)
- Shell Building: 8–10 layer ceramic shell with mullite and fused silica for large-casting thermal shock resistance
- Dewaxing & Firing: Controlled autoclave dewaxing (ramp rate < 2°C/min), shell firing at 1050°C
- Pouring: QT600-3 ductile iron poured at 1400–1450°C with magnesium nodularization treatment
- Normalizing: 900°C for 2 hours, air cooled to achieve pearlitic-ferritic matrix
- CNC Machining: 4-axis CNC for bearing bores (H7 tolerance, Ø120–250mm), mounting flanges, adjustment screw threads
- Hardfacing (Optional): Tungsten carbide overlay on wear surfaces per customer specification
- Pressure Testing: Not required (structural component), but crack detection via magnetic particle
- Inspection: CMM dimensional, magnetic particle (ASTM E709), ultrasonic (ASTM E2375), hardness mapping
Key Features
- High Structural Rigidity: QT600-3’s 600 MPa tensile strength and 190–270 HB hardness provide exceptional resistance to impact and vibration loads
- Large-Format Casting: Sand casting capability up to 55 kg produces complex drum housing geometry in a single piece
- Precision Bearing Bores: CNC-machined to H7 tolerance for Ø120–250mm bearing seats, ensuring drum rotation concentricity
- Vibration Damping: Ductile iron’s inherent damping capacity (3× better than steel) reduces drum vibration, improving cutting surface finish
- Wear Protection: Optional tungsten carbide hardfacing on asphalt-contact surfaces extends service life by 3×
- NDT Verified: 100% magnetic particle + ultrasonic testing ensures internal soundness for safety-critical structural application
Application Fields
- Cold planers / road milling machines (Wirtgen, Roadtec, Caterpillar compatible)
- Asphalt recyclers / stabilizers
- Concrete scarifiers / scabblers
- Trench milling machines
- Mining and quarry milling equipment
Why Choose Ningbo Ruican
Ningbo Ruican’s 17+ years of large-format ductile iron sandt casting, combined with IATF 16949 certification, positions us as a trusted partner for road construction equipment manufacturers. Our QT600-3 drum housings are field-proven in Tier 1 OEM cold planers across North America and Europe, with documented service life exceeding 4,000 operating hours. We provide comprehensive DFM support, rapid prototyping via 3D printed wax patterns, and full NDT documentation.
