Heat Treatable Structural Steel Tubing Needed

[RodneySparks]

Hello!

I'm working on a design that depends on the availability of rectangular steel tubing in 3" x 5" and 3" x 10" sizes, both 3/8" wall thickness. My design calls for a yield strength of about 130 ksi, and is weight sensitive, so throwing more mild steel at it doesn't make sense. We'd rather heat treat it than use more material.

Are there any structural steel grades, welded or seamless, that have a composition comparable to a 4000 series steel? For that matter, is there a source for 4000 series (4130, 4140, etc.) steel in this structural shape?

Thanks,

-Rodney Sparks

Rodney Sparks, Consulting Engineer
Creative Spark Engineering -

http://www.creativesparkengineering.com

Specializing in conceptual, system-level and detail design of electromechanical products and subsystems.

 

[EdDanzer]

You may have to settle for A514 tubing in that size (100,000 psi yield).

Contact a domestic structural tube manufacture to be sure.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[redpicker]

Do you have to stay with a rectangular cross section? Oil Country goods (casing, tubing, and pipe) are commonly produced using 4100-type chemistries. Obviously, these are only produced in circular cross-sections. Depending on how much you need, you might be able to get a manufacturer to modify the heat treatment to hit the yeild strength you want.

rp

 

[RodneySparks]

Thanks for the suggestion. I may have to do that.

However, I want to heat treat the welded assembly, so I don't necessarily need tubing that is already quenched and tempered. Is there a commonly available steel under a different spec than A514 that has a similar composition that I could quench and temper after welding in order to arrive at >=100 ksi?

Rodney Sparks, Consulting Engineer
Creative Spark Engineering -

http://www.creativesparkengineering.com

Specializing in conceptual, system-level and detail design of electromechanical products and subsystems.

 

[RodneySparks]

redpicker: Yeah, it's gotta be rectangular. I've found plenty of round tube for some other parts I've designed. Thanks for the suggestion though!

-Rodney

Rodney Sparks, Consulting Engineer
Creative Spark Engineering -

http://www.creativesparkengineering.com

Specializing in conceptual, system-level and detail design of electromechanical products and subsystems.

 

[EdDanzer]

It may be possible to have tube custom fabricated from 8620 plate or 4130 and heat treat after welding but it will be expensive.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[unclesyd]

Your 3x5 is about the cut off on most heat treatable alloys.
Here are two suppliers of 4130 rect tubing. We used this a lot in building machine frames.

http://www.factorysteel.com/aircraft-tubing.htm

http://www.boiler-tubes.com/Seamless-Mechanical-Tubing.html

If you can use 70,000 min yield you might take a look here.

http://www.tubularsteel.com/products_squarerect.asp