The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Bondable, wearable under extreme pressures

In the railroad industry wear of a rail on curves is 10 times greater than wear of rail on straight track. This is caused from laterial forces between the wheel of a train and the rail. These lateral forces reach 30,000 PSI. What will slow this curve rail wear? It must be bondable to existing rail, wearable to equal straight or tangent track wear and have a ease of application to the existing installed rail. The key is a material that will withstand pressures of 30,000 PSI laterial forces. Could it be a plating of another metal by plasma spraying, could it be a plastic or adhesive?

Paul Griffin
- Faribault, MN, USA

---

 

Dear Paul,

May I suggest that you think differently re the to-be-expected heavier wear on curves.

Back before WW2 the Berlin underground system was supplied with Schienen (i.e., rails) specifically for these conditions.

They were made by the Bochumer Verein, AG. in the Ruhr valley. How? Easy! During the pouring process of the molten metal for making rails using, in those days the cast iron from Bessemer converters, inside the mould they installed a perforated plate which would be and was 'dissolved' by the molten metal. This took up about 1/8" of the mould capacity. Into this smaller aperture they simultaneously co-poured an abrasion resistant steel (High silicon? ... I forget). Then when the finished block of metal was cooled down and released from the mould, it went through rolling mill processes taking care, of course, that the small but high abrasion resistant metal would form the top or most of the top of the wear section.

That Company apparently no longer makes rails but was taken over by Krupp. During the war they employed 25,000 people but in the 50's they were still making railway lines along with points, etc.

...just thought that that might be of some interest to you when and if you ever get to order NEW rails.

Hoffentlich ist das Ihnen behilflich ...Cheers!

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

---

Be careful now, we don't want a nation full of locomotives and flat cars with worn out wheels. But I can't see any good reason that a hard-surfacing material couldn't be applied to rails with flame spray equipment.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
 

---

Actually, Roger Johnson and his cohorts at Batelle Northwest Labs developed an electrospark coating for just this application. I think they even worked out the economics. I know it was tested in the field. I don't think spray coatings will work. The adhesion is not good enough.

Jim Treglio - scwineryreview.com
PVD Consultant & Wine Lover
San Diego, California
 

---

 

Dear Paul,

I think Freeman Newton is thinking of a 14% manganese addition to the rails. There is still at least one German manufacturer of this type of rail with US support-offices. The Hadfield alloys found great use in early US jail bars as well as railway operations. The cold working from files, saws and hammers is enough to create a surface glaze that is nearly impossible to abrade through. With high toughness and fatigue resistance, these alloys are regularly used in the mining industry for overlays to prevent erosion and wear from sliding debris. Hardnesses above Rc 40 in a weld overlay are possible without fatigue cracking.

I am sure these alloys are available as welding wire, but I haven't been able to locate anything in powder form.

Grüß aus "die Bahn",

Dave Hass
- Oklahoma City, USA

---

 

Hi,

Depending on the carbon content, which I suspect to be high enough (over 0.50%), on the microstructure actually present (already quenched?) and on other complex factors, there could exist the possibility to induction or flame harden the working surfaces in-situ. This seems so obvious that I would be surprised it hasnt been tried and discarded, but if not it will require a lot of investigation beyond the scope of this forum.

Guillermo Marrufo
Monterrey, NL, Mexico