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Forged Monobloc Passenger Car Railway Wheel of AAR ST

Forged Monobloc Passenger Car Railway Wheel of AAR ST

Product No.：202672915372
Price：nogotiation
Material：high-quality carbon steel
Standard：AAR
mould charge：yes
Production time：60
weight：215
Package：Wooden Box
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1. Product Overview

Product Name: Forged Monobloc Passenger Car Railway Wheel of AAR Class B

Product Definition: This product is a forged steel monobloc wheel manufactured in accordance with the Association of American Railroads (AAR) Class B material standard for passenger car applications. Produced via a single-stage hot forging process, it is specifically designed for passenger railway vehicles operating under moderate to medium axle loads and moderate tread brake conditions.

Applicable Standards:

AAR M-107 / M-208 (Wheel Manufacturing and Supply Technical Conditions)
AAR S-660 (Wheel Design Load Specifications)
AAR S-669 (Wheel Plate Fatigue Analysis and Evaluation Method)

2. Material Specifications

2.1 AAR Class B Chemical Composition Requirements

Element	Content Range (wt. %)	Remarks
C	0.57 – 0.67	Primary strengthening element; ensures hardness and wear resistance
Si	≤ 0.40	Deoxidizer; improves strength
Mn	≤ 0.90	Enhances hardenability
S	≤ 0.040	Impurity control
P	≤ 0.040	Impurity control
Cr	≤ 0.30	Optional addition; improves hardenability
Cu	≤ 0.30	Residual element control
Ni	≤ 0.30	Residual element control
Mo	≤ 0.08	Optional addition; controls bainite formation

Source: Reference to ISO 1005-6 and corresponding AAR steel grade requirements

2.2 AAR Class B Hardness and Mechanical Properties

Property	Requirement	Description
Flange Hardness (HBW)	277 – 341	Ensures wear resistance and spalling resistance
Tensile Strength	≥ 900 MPa	Ensures load-bearing capacity
Elongation	≥ 12%	Ensures ductility and toughness
Metallographic Structure	Predominantly Pearlite (area fraction ≥ 90%)	Avoids softening phases such as bainite and ferrite

Application Conditions: Class B material is suitable for moderate tread brake conditions, heavier wheel loads, or applications involving off-tread braking and split-duty brake operations.

3. Design and Manufacturing

3.1 Forming Process

Process Route: Steel ingot melting → Hot forging → Heat treatment (tread quenching) → Precision machining → Non-destructive testing → Final inspection and release
Process Advantages: The forging process enables continuous metal flow lines along the wheel contour, providing superior impact toughness and fatigue resistance compared to cast wheels. The subsequent tread quenching induces a compressive residual stress layer on the tread surface, significantly extending the rolling contact fatigue life.

3.2 Design Features

Monobloc Construction: Eliminates stress concentration points associated with assembled tyre-and-center structures
Plate Design: Fatigue-verified in accordance with AAR S-669, satisfying combined mechanical and thermal loading conditions
Tread Profile: Available in AAR standard tread profiles or custom designs per customer requirements
Wheel Diameter Range: Typically Φ28″ – Φ42″ (711 mm – 1067 mm), customizable upon request

3.3 Quality Control and Inspection

Inspection Item	Method	Standard Requirement
Chemical Composition	Spectrometric Analysis	AAR M-107
Metallographic Structure	Microscopic Examination	Pearlitic structure; no pro-eutectoid cementite
Hardness Testing	Brinell Hardness (HBW)	Multi-point inspection on flange and hub
Ultrasonic Testing	UT Inspection	100% inspection for internal defects
Magnetic Particle Testing	MT Inspection	Surface defect detection
Dimensional Accuracy	3D Coordinate Measurement	Per customer drawing + standard requirements

4. Typical Applications and Performance Advantages

4.1 Typical Application Scenarios

Parameter	Specification
Applicable Vehicle	Passenger Car / Passenger Coach
Typical Axle Load	11 – 18 tons
Maximum Service Speed	≤ 120 km/h (subject to design optimization)
Braking Method	Tread braking / Off-tread braking / Split-duty braking

4.2 Performance Advantages

Superior Fatigue Resistance: AAR Class B material combined with the forging process is fatigue-verified per AAR S-669, satisfying fatigue life requirements under combined mechanical and thermal duty cycles
Excellent Wear Resistance: The Class B hardness grade (277–341 HBW) strikes an optimal balance between wear resistance and toughness, well-suited for frequent braking operations in passenger service
Spalling Resistance: Tread quenching induces a compressive residual stress layer, effectively mitigating rolling contact fatigue-induced tread spalling
International Standard Compatibility: AAR standards are widely recognized across North American and global railway industries; the product is compatible with mainstream bogie interfaces in North America, Asia, Europe, and beyond

5. Ordering Information

Item	Description
Product Code	FMRW-CLASS B-[Wheel Diameter]
Standard Compliance	AAR M-107 / M-208 / S-660 / S-669
Delivery Condition	Finished machined product, coated with rust-preventive oil
Packaging	Secured in wooden crates or steel frames, suitable for sea/land transportation
Warranty	Full compliance with AAR standards; individual inspection reports provided with each shipment