Relative Hardness of Steel Wheels and Tracks

[arcticguy00]

Can anyone offer some guidence on the recommended hardness of steel tracks under a 40,000 lb load? Our load travels back and forth, repeatedly over two parralel tacks each 4 feet long. Two wheels are V-grooved and guided on one steel track by an inverted angle welded on. The track surface will be smooth to +/-0.005". I'd like it to last 9000 cycles, but unless the track is hard enough I am worried about premature wear resulting from brinnelling type deformation of the track. Over spec'ing too hard a track track will affect are ability to weld the inverted angle to guide the V-grooves and to machine the surface.

Questions:
1.Any thoughts on what hardness should be spec'd for the steel tracks ?
2. Is it necessary to match track hardness to the wheel hardness so neither prematurely deforms from the forces they impose on each other?

Many thanks to all who send me their thoughts.

 

[dvd]

You can find some good information on v-grooved wheels and track at:

http://www.loadrunners.com/

Download the catalog and review the customer designed track requirements. You should consider using the LoadRail instead of your inverted angle. We have welded it before, but bolting onto a welded bar would allow you to change track in the event of wear.

Are you located way up north like your name implies? There may be other considerations in your track and wheel selection.

 

[MASSEY]

http://www.pcimfg.com/

is another source.

On page # 47 pdf Track Roller catalog they have track capacities for a variety of hardnesses for tracks.

As for which should be harder, the roller or the track, ask which you would rather replace. Pick one or the other or you will have to replace both when they wear.

Both above companies offer "Eccentric" rollers so adjustments can be made after the roller wears significantly.

I also recommend purchasing load rails, it 'seems' more economical than the labor involved in welding, machining, etc. your own track.

 

[CouplingKing]

Be very careful with hardened steel and welding. The heat affected zone from a weld will decrease/remove the hardness you have created.

Also consider the case depth you require, select a process that will give sufficient strength and hardness to the sub surface regions, rather than a superficial surface treatment.

Carburising and nitro carburising offer good case depth, and hence the opportunity to regrind in the event of damage.

CK

 

[EdDanzer]

The travel speed will have some effect. You may want to consider using rail road iron instead of angle iron. It is used in sawmill carriage tracks, bridge cranes, machine tools, ect.