welding railways

By jwright650 (*****)

Date 05-07-2004 10:01

Are you planning to full pen splice two pieces of that rail?
John Wright

By swnorris (****)

Date 05-07-2004 15:09

Hi gunmonk,

From the dimensions you provided, it sounds like what you have is either a 65 or 70 pounds per foot A.S.C.E. rail. I think the 70# is no longer in production. The 65# is 4 7/16" tall and 2 13/32 wide at the rail, and 70# is 4 5/8" tall and 2 7/16"wide at the rail, both weights conform to ASTM A759. I don't have access to the ASTM Specification, but the rail is probably a high carbon steel. It sounds like you're planning to use some sort of oxyfuel gas welding process, which I don't know too much about, so I wouldn't know how much it differs from stick or wire welding in terms of preheat and postheat procedures, but for stick or wire welding on such an application, preheat temperatures of around 800-1000 degrees F are necessary to prevent cracking, and postheat is needed for stress relief at around the same temperature as the preheat, and allowed to cool naturally. Mckay Hardalloy 118 rods or Railend 932-0 rods and wire are two good filler metals. Maybe they produce a filler metal for your application.

By billvanderhoof (****)

Date 05-08-2004 04:21

Watched some railroad guys put in a siding once and they used O/A to build up a little ramp where the rail sizes were different. When asked why not arc weld they said it tended to be brittle under the weld and the ramp would just peel off. This basically confirms everything swnorris says about carbon content pre/post heat etc. It also confirms the possibility of O/A welding.

Now a word from the legal department- If this is in any way a safety critical device (read that as not lying flat on the ground) you should not attempt it. It is really easy to produce nice looking welds with O/A that are actually just worthless cold laps which can fail without warning.

If you proceed- That railroad guy had a BIG tip you will need one too. You will need a big acetylene tank to feed gas fast enough. The more you can preheat the easier it will be to melt the base metal so preheat a lot. Cool slowly.

Consider designing and making some connecting plates and bolting this together.

Bill

By Pascal

Date 05-10-2004 22:48

Hi Gunmonk,

I've seen alot of railway welds done by thermo-welding. It looks like a mini-blast furnace that you stick over the join. Its strong, produces good results and looks cool when performing it!

Pascal.

By billvanderhoof (****)

Date 05-12-2004 06:43

Google for "thermite welding" almost 700 results. The process involves a mixture of aluminum filings and Iron oxide (copper oxide apparently works also). A portion is heated, sometimes by allowing a piece of magnesium ribbon to burn down into the thermite. When the kindling temperature is reached the aluminum starts to burn using the the iron oxide as a source of oxygen. The result is aluminum oxide, free iron (molten) and lots of extra heat. The crucible that is used for a reactor usually has a hole in the bottom thru which the molten metal runs into the area to be welded. Clay or sand dams are used to prevent the metal from flowing out of the weld. The aluminum oxide slag floats on top. The process does indeed look neat. Since thermite is also used to make incendiary bombs you might get curious looks in these times if you try to buy it.
Bill

By Pascal

Date 05-12-2004 22:46

That is true, you might get some curious looks but it's used widely as it performs well. In Aus, it would be one of the most commonly used techniques for welding rails.