Why Choose Xtek?

Xtek Crane Wheels

Crane Maintenance Spending Survey Results From AIST Crane Symposium

Brakes 16%

Motors 12%

Bearings 11%

Gearing 10%

Couplings 5%

Shafting 3%

Wheel Assemblies 43%

Others & Unknown 16%

Spalled Tread 2%

Worn Tread 9%

Axle Breakage 13%

Bearing Failure 21%

Worn or Broken Flange 39%

Wheel Assembly Reasons for ReplacementSurvey Results From AIST Crane Symposium

Typical Wheel Problems

Spalling - Material or hardness is not capable of carrying the load

Broken Flanges – Flange hardness to brittle to resist impact stresses

Wear – Related to the hardness properties of the wheel and the operating conditions

Crane Wheel Performance

Sub-Surface Shear StrengthHighest Stress

at Impact

LOAD - Heat treatment places wheel tread in compression and provides a deep case

FRACTURE – Tough and ductile core to address shock loads during operation

WEAR – High surface hardness extends wheel life and reduces friction with the rail

Compliance with AIST/AISE Technical Report No 6, Dated June 2005

Resistance to Spalling, Flange Failure and Wear

Heat Treatment places the wheel

tread and flanges in compression

allowing for higher load capability

Contour case hardening pattern

provides a ductile core in the flanges

Surface hardness provides wear

resistance

Xtek Contour Case HardeningXtek Contour Case Hardening

Xtek Wheel with WORN Tread and Flange

Through Hardened FlangesHigh Risk of Fracture

Through Hardened FlangesHigh Risk of Fracture

Xtek Heat Treating

Operations

Xtek Crane WheelContour Case Hardened

Surface Hardness58 – 62 HRC

Surface Hardness58 – 62 HRC

Soft CoreFlanges Not

Through-Hardened

Soft CoreFlanges Not

Through-Hardened

Depth of Hardness.160 – 200”

Depth of Hardness.160 – 200”

AISI 1055Forged Steel

Core Remains Ductile

AISI 1055Forged Steel

Core Remains Ductile

Allowable Wheel Loads(24” Wheel Diameter)

63

88

75

105 104

146

117

164

0

20

40

60

80

100

120

140

160

180

Th

ou

san

ds

of

Po

un

ds

105 135 175 171ASCE Rail Section

Heat Treated (320 BHN)

Case Hardened (58 HRC)

RESULT: 40% INCREASE IN CAPACITY

Operational ConsiderationsIndustry Standards

AIST Straight Tread Bridge Drive Wheels Shall Have Tread

Diameters Matched Within 0.010” Maximum of Each Other When Mechanically Connected

All Other Applications, Including Tapered Tread, Shall Have Bridge and Trolley Driver Wheels Matched Within 0.030” Diameter Maximum of Each Other

CMAADrive Wheels Shall be Matched Pairs Within 0.001” per

Inch of Diameter or a Total 0.010” on Diameter, Whichever is Smaller

PRECISION FINISHING OF HARD TREAD

US Navy Crane CenterMIL-Handbook #1038

Weight Handling Equipment (Design Criteria)

Section 5.3.11 – Travel Wheels - Page #150:

“There is no detriment to large differences between the wheel and rail head hardnesses. Experience suggests that wear on both can only be improved by increasing the hardness of either the wheel, rail head, or both.”

Case Study: Crane Wheels

Problem: Application = Steel Mill Scrap Yard Crane Current Wheel Product = Rim Tough Wheel, 320 BHN Problem = Wheels replaced every 9 months Primary Cause = Tread wear and flange wear

Solution:

Test established with Xtek contour hardened track wheels

Results: Xtek wheels were monitored for 36 months

Still in service at end of test

Savings of $10,200 per wheel during the 36 month test and going… Xtek wheel cost $ 922 / each The existing wheel cost $650 / each

Three additional wheels would have been purchased

Labor cost to change a wheel assembly from the crane = $600 / each Three additional wheel assembly exchanges would have occurred

Reconditioning changes avoided during the test = $2,150 / each Three reconditioning expenses were avoided

This test has also benefited the mill by the avoidance of unscheduled downtime and now offers the potential for a reduction in inventory

Case Study: Crane Wheels

WHEEL ASSEMBLIESWHEEL ASSEMBLIES

Crane Wheel Assembly Reconditioning

Disassembly Inspect Reverse Engineer Failure Analysis Manufacture Assemble

Why Xtek?• Crane and Material Handling

Equipment expertise• Involved in Crane and

Material Handling Standards• In House Heat Treatment• Full line of material

alternatives to address application requirements

• 60+ Mechanical, Metallurgical and Service Engineers

• World wide steel mill experiences

• Service capabilities• Reverse engineering• Failure analysis• Inventory management• Drawing and data

management• Emergency response

capability• Active in all Nucor flat

rolling facilities and most of the structural mills

• ISO Certified

Thanks for your consideration!

Xtek Crane Wheels