What is involved with heat treating steel

Farwell · Feb 16, 2006

I use metal rain gutters capped at each end when I need a long narrow container for liquids. I use plastic gutters when soaking things in harsh chemicals. Both have worked very well for me and the cost is not out of line.
Farwell

KennethBrown · Feb 16, 2006

I have heated a metal till red and then covered it in sand before. This allows it to cool slowly and increases the strength. I don't know the right temps or how much it increases it, just was told to do it and it worked.

PineRidge · Feb 16, 2006

I've heard of that same process, only using salt instead.

scott_vt · Feb 16, 2006

( That link that MossRoad gave has good information in it. I work a lot with 4140, using it for holder block (mold base steel) for plastic injection molds. I buy it in that hardness (around 32Rc/35Rc) and machine pockets, etc for the mold inserts that go into it. That's usually the most common heat treat for that type of steel.

You can further heat treat it by case hardening it where it will become "stiffer". Case and carburize 1/16" deep will give you an outer layer that's super hard (about 60Rc) with interior remaining at about 35Rc. It will increase all aspects of its strength...tensile, elasticity etc. But it will also be more brittle on the casing.

This I would send out to a heat treating shop because the tempering of ANY steel is the most critical and I doubt you can hold temperatures at length of time required to obtain what you desire. Just quenching after heating without tempering will give you a rock hard, super britlle piece of steel.

)

Rob,
I would have to agree with you, although the others have some good ideas, trying to quench that large of a piece without an adequate oil resevoir is only looking for poor results IMHO.

scotty /forums/images/graemlins/grin.gif

turbo36 · Feb 16, 2006

Look in the yellow pages under Steel treating or Heat treating for a local source and let the professionals do it, the charge should be $50-$75 but it will be well worth it.

kennyd · Feb 16, 2006

Man,
What are you up to now!!!!!!!! /forums/images/graemlins/wink.gif

PineRidge · Feb 16, 2006

Like others mentioned, you really have to look at the elasticity in buckling situations, and you'd probably have the most gains if there is any way to increase the size of your stock.


After doing some further homework today and calling a local company that does heat treating I decided to just take Chad's advice.

I'm dropping the 6' for of 7/16" hex steel and moving up to a 3/4" solid steel shaft. For what I need it to do there shouldn't be any flexing problems with the heavier material. Thanks Chad for giving me a wake up call.

Kenny let me see if this thing works first, then I'll let you in on the project, as it's almost finished.. /forums/images/graemlins/wink.gif

TOMDUALLY · Feb 17, 2006

IF THE OUTSIDE DIAMETER ISN'T A FACTOR TRY SLIDING A PIECE OF 1/2" STEEL PIPE OVER IT . THIS WOULD STIFFEN IT UP CONSIDERABLY.

John_Mc · Mar 11, 2006

Pineridge -

How did your project with the heat treated steel work out?

Too bad I'm not still based in NW Ohio... the company I work for has two manufacturing facilties there making steel spring wire up to just over 5/8 diameter in a variety of alloys (probably will be pushing that up to 3/4" or so in the near future). We almost alway send up with scrap lengths from our coils. I probably could have gotten you some 6 foot lengths for free... of course they'd already be hardened, so machining them would be tough (you'd probably have to partially anneal the parts you wanted to work).

One of our competitors is right in your area (NE Ohio -- Cleveland area). They probably have similar scrap lengths, but I don't think the go as large as we do in diameter. You'd need an inside contact to scarf up some free ones... or even to convince them to sell them. For most of us in this business, 10,000 pounds is a small order.

Can you let us in on what you were making, or is this a top secret project?

BTW... a lot of these chrome alloys make great spring steel, but they are tougher to heat treat than regular high carbon steel... especially if you are trying to do it in your back yard. Done wrong, they can be very brittle and shatter like glass (sending shrapnel flying). Probably not a bad decision to have it professionally heat treated.

John Mc

Cottonhawk · Mar 12, 2006

That's a better idea than heat treating iron rich Fe-Cr-Mo alloy.
If you decide to heat treat Fe-Cr-Mo or any other alloyed steel, I'd use a pro-shop. If you decide to do it yourself, I'd follow the detailed phase diagram and the established heat treat procedures. Otherwise you may end up with a completely different phase (crystal structure) and physical attributes than you're looking for.