High Manganese Grinding Roller Grinding Ring for Raymond Mill

I.1ntroduction

High manganese steel grinding rollers and grinding rings are the core wear parts of Raymond mills, directly responsible for material grinding. The two components work together to form the grinding interface—the roller rotates under centrifugal force, pressing tightly against the inner wall of the grinding ring to crush and grind the material into powder. The wear resistance of these components directly determines the equipment’s operational efficiency, finished powder fineness, and maintenance costs.

2. Material Properties 

2.1 Base Material  Manufactured from high manganese steel (Mn13, Mn18Cr2) , which features a unique work hardening characteristic:

 · Initial Hardness: Approximately 200 HB (excellent toughness for easy processing and installation)

· In-Service Hardness: Under impact and rolling pressure, the surface rapidly hardens to 450-550 HB

 · Core Toughness: Maintains high toughness throughout to prevent brittle fracture。

2.2 Chemical Composition (Typical Values) 

 Grade C (%) Mn (%) Si (%) Cr (%) P/S (%) 

Mn13 1.1-1.4 12-14 0.3-0.8 ≤0.5 ≤0.04 

Mn18Cr2 1.1-1.3 17-19 0.3-0.8 1.5-2.5 ≤0.04

3. Structural Design 

 3.1 Grinding Roller 

 · Structure: The roller assembly consists of a roller shaft, bearings, and the outer roller sleeve 

· Shape: Tire-shaped annular component with concentricity between outer diameter and inner hole controlled within ±0.5mm 

· Connection: Suspended from the star rack, revolving around the main shaft while rotating on its own axis

3.2 Grinding Ring 

 · Structure: One-piece annular casting with the inner wall serving as the grinding surface 

· Installation: Fixed to the inner wall of the machine frame, concentric with the grinding roller 

· Working Surface: The inner diameter surface is precision-machined to ensure accurate fit with the roller sleeve outer diameter

4. Manufacturing Process 

 4.1 Casting Process 

 · Method: Sand casting or precision casting 

· Pouring Temperature: Approximately 1450-1480°C 

· Characteristics: Ensures dense casting structure free from porosity, shrinkage cavities, and other defects 

 4.2 Heat Treatment

 – Water Toughening 

· Heating: Raise temperature to 1050-1100°C, hold for 2-4 hours 

· Quenching: Rapid immersion in water (water temperature ≤30°C) · Purpose: Achieve uniform austenitic structure, eliminate carbide precipitation, ensure work hardening capability 

 4.3 Machining 

 · Rough Machining: Turning of outer diameter and end faces with machining allowance 

· Finish Machining: Ensure dimensional tolerances and surface roughness (Ra ≤6.3μm) 

4.4 Quality Inspection 

 · Composition Analysis: Spectrometer testing for chemical composition 

· Hardness Testing: Brinell hardness tester · Metallographic Analysis: Inspect austenite grain size and carbide distribution · Flaw Detection: Ultrasonic or magnetic particle inspection to identify internal defects 

5. Performance Specifications 

 Parameter Value 

Initial Hardness 180-220 HB 

In-Service Hardness ≥450 HB 

Tensile Strength ≥750 MPa

Elongation ≥20% Impact Toughness ≥150 J/cm² 

Service Life 2-3 times longer than ordinary carbon steel