Welding for another reason

[Gary Fowler]

Even though mild steel cant be hardened doesnt mean that welding rods wont harden when applied. I once had a machinist ask me to run a "hot bead" around a coupling that was on a piece of cold rold steel for deep penetration as he was going to machine it out flat and remove the surface weld. I ran a hot bead using 3/32 6010 at about 150 amps and gave it back to him. A few minutes later he came back and wanted to know what I had done as the weld was breaking his cobalt cutting tools it was so hard. I had to take a rosebud and heat the whole piece up to about 1250F and let it cool slowly to anneal the weld metal enough for him to machine it. I guess the high amps and the quick quenching of the weld metal on the solid rod did some sort of hardening on it. I do find that a high amp 6010 rod is much harder than running low amperage for some reason. There is no addition of carbon to it, but it does harden.

 

[easygo]

If I do end up buying hard surfacing rods, are they easy to restart? I only have to put down 1.5-2" long beads at the time and then restart on the next "tooth" . Also. Roughly how many inches of weld can I get out of one rod? I know it depends on the "travel speed" but any rough estimate? Is it similar to 60xx or 70xx rods that I could try how much hard surfacing rod I would have to have to do this project?

 

[LD1]

I have never had any trouble with re-starting. But if you do, it will most likely be like 7018 where they glaze over. If they do, I'd have a separate peice of steel laying there (ungrounded) that you can tap/scratch the rod on before each restart.

As to the lengh you get out of each rod, that depends on how long you hold/build up. But IMO, they weld like any other rod, you can go fast for a light buildup, or take you time (consuming more rod) for more build-up.

In your case, I'd go about at a normal pace, try not to burn too deep into the base metal (and dilute the hard material as you or someone else already mention), and then if you want more, do a second pass.

Either way, once you buy a box, you will get a really good feel for then within a rod or two. But nothing is out of the ordinary. They are like running any other rod IMO.

 

[Gary Fowler]

You want to run them pretty cold to prevent dilution of the weld metal for maximum hardness. With a 1/8" x14" rod, I would think that you could get at least 9 or 10" of weld metal as you would just drag it and pretty much let the rod burn inch for inch. Brain55 has done lots of hardfacing so his advice might be pertinent for you.

 

[easygo]

Thanks for the great advice. I will follow the guidelines and will look into prices since it sounds like I would not need more then 8-10 electrodes. It might be worth coughing up some extra $. Also. Are these hard surfacing electrodes supposed to be kept like 7018 or it doesn't matter so much?

 

[Jesse masterson]

I'm not saying this works cause I never tried it but I read an article on net about someone who mixes a cup of Calgon dishwashing liquid and dip the steel in it something about the bubble action. It harder steel all through it from a hardness of 35 to a hardness of 48