Crane Wheel / Crane Rail

Interface

Testing of Material Wear Properties

History of Wheel / Rail Interface Materials and Heat Treatment

No test data available for Hard Wheel / Soft Rail Combination

Information almost all anecdotal

Application successes and failures

Many variables to consider

Crane Operation

Runway and Building Condition

Wheels and Rails

Sizes, Materials, Heat Treatments

Users concerned about switching to Hard Wheel

Initial belief is the Hard Wheel may act like a tool and cut into the soft rail

Wheel - Rail Interface

Sub-Surface Shear

– Leads to Spalling

Sub-Surface Shear

Leads to Spalling

High Surface Stress at

Impact – Leads to

Flange Breakage

CONTACT STRESS -

LEADS TO

ADHESIVE WEAR

Adhesive Wear on Flanges Non-Lubricated Metal-to-Metal Contact

Adhesive Wear on Flanges Non-Lubricated Metal-to-Metal Contact

200

300

400

500

600

700

800

Bri

ne

ll H

ard

ne

ss

Hard Wheel

Test Sample

581 BHN

(56 HRc)

Soft Wheel

Test Sample

280 BHN

Hardened Wheel

578 - 690 BHN

(56 - 62 HRc)Hardened Wheel

420 - 481 BHN

(45 - 50 HRc)

Rim Toughened

Wheel

321 - 363 BHN

Cast Wheel

250 - 300 BHN

Wheel Test Samples

v. Wheel Hardness

Materials AISI 1055, 1070, 4140

Rim Toughened based on ASTM A504 Class C

Rail Test Samples

v. Rail Hardness

200

250

300

350

400

450

Bri

ne

ll H

ard

ne

ss

Soft Rail

Test Sample

285 BHN

Control

Cooled Rail

248 - 320 BHN

Head

Hardened Rail

321 - 388 BHN

Material based on ASTM A759

Carbon 0.67% - 0.84%

The Battelle Institute Information on Test Laboratory

Technology Development for Industry and Government

Based in Columbus, Ohio

7,500 Research Scientists and Engineers

Euro 1 Billion Annually in Revenue for Research

Serves over 2000 Companies and Government Agencies

50-100 Patents / year

Operates 4 National Laboratories

Material Test Parameters

Pressure = 13.8 MPa

Stroke Length = 28 mm

Cycle = 2 Strokes

Speed = 25 mm/sec

Delay Between Stroke = 4.9 sec

Room Temperature

Air Blown to Clear Debris

Battelle

Test Rig

Wheel Wear

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Cycles

Wear

Dep

th (

mm

)

Soft Wheel

v.

Soft Rail

Hard Wheel

v.

Soft Rail

Rail Wear

0.00

0.50

1.00

1.50

2.00

2.50

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Cycles

Wear

Dep

th (

mm

)

Soft Wheel

v.

Soft Rail

Hard Wheel

v.

Soft Rail

Material Test Samples after 10,000 Cycles

Hard Wheel Material

Soft Rail Material

Soft Wheel Material

Soft Rail Material

Wear Depth Test Results 10,000 Cycles

Worst combination for wear is Soft Wheel – Soft Rail

Best combination for wear is Hard Wheel – Soft Rail

2.118

0.068

1.158

0.053

0.00

0.50

1.00

1.50

2.00

2.50

Soft Rail-Soft Wheel Soft Rail-Hard Wheel

We

ar

De

pth

(m

m)

Rail Wear Wheel Wear

Crane Wheel / Crane Rail

Interface

Testing of Material Wear Properties

Thanks for your attention!