Why Choose Xtek? Xtek Crane Wheels. Crane Maintenance Spending Survey Results From AIST Crane...
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Transcript of Why Choose Xtek? Xtek Crane Wheels. Crane Maintenance Spending Survey Results From AIST Crane...
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