Best suited material...suggestions????
Best suited material...suggestions????
(OP)
Hi All,
New here...My application is: reaching into a moving belt
furnace with fully automated robotic arm, to pick up a
powdered metal part, and place it in a forging die. The
temperature in the oven is approx. 1600f. It is a continous
operation with aprox. a 7 sec. cycle time(trying to show
heat environment, hot, cold etc. in,out) Robot arm frame
is water cooled, but hardware is not. The part in question
is the actuating rod. Previous materials have been 304, 316, and 625..Trying 330 right now..Cost and availibility
a problem with 625. A 1 inch square nut with a .500 hole thru, gets welded to the .500x26" rod, welding with stick
(308 rod)right now trying 304 nut, and 330 rod. Stress
relieving after weld @650f, for 2 hours, then turn furnace off and cool down with the furnace. Eventually part fails
(cracks or completely breaks in half,always at weld)
Usage is constant, and would like to help customer by
addressing the problem...Any suggestions from you guys would be greatly appreciated....KJC
New here...My application is: reaching into a moving belt
furnace with fully automated robotic arm, to pick up a
powdered metal part, and place it in a forging die. The
temperature in the oven is approx. 1600f. It is a continous
operation with aprox. a 7 sec. cycle time(trying to show
heat environment, hot, cold etc. in,out) Robot arm frame
is water cooled, but hardware is not. The part in question
is the actuating rod. Previous materials have been 304, 316, and 625..Trying 330 right now..Cost and availibility
a problem with 625. A 1 inch square nut with a .500 hole thru, gets welded to the .500x26" rod, welding with stick
(308 rod)right now trying 304 nut, and 330 rod. Stress
relieving after weld @650f, for 2 hours, then turn furnace off and cool down with the furnace. Eventually part fails
(cracks or completely breaks in half,always at weld)
Usage is constant, and would like to help customer by
addressing the problem...Any suggestions from you guys would be greatly appreciated....KJC





RE: Best suited material...suggestions????
I would stick with the 330 ss actuating rod, and use Inconel 182 filler metal to join the 304 ss nut to the 330 ss rod instead of 308 filler metal. The 330 ss normally exhibits high resistance to thermal shock. The higher nickel and chromium content will provide increased oxidation and creep strength. Inconel 182 is a nickel base electrode (SFA 5.11 ENiCrFe-3) with excellent ductility, and will handle the thermal stresses with no problem.
No stress relief is required after welding.
RE: Best suited material...suggestions????
RE: Best suited material...suggestions????
RE: Best suited material...suggestions????
Once you get the weld straigntened out your next failure will probably be realted to thermal fatigue.
Then you can start trying to get people to accept that you need to go to Ni based materials. Without going crazy Alloy X may be your best option.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Best suited material...suggestions????
RA330 hex nuts are available from Rolled Alloys as is threaded bar if that helps.
Other issue is 304 expands more than RA330 at 1600F. 304 expands roughly 10% more on each cycle. That can induce additional stresses that lead to cracking.
If an all RA330 welded with RA330-04 does not do the trick then I would suggest looking at alloy 600 welded with 182 rod or 82 wire. Alloy 600, like RA330, will not embrittle from sigma phase so it retains its ductility and it has an even lower coefficient of expansion than RA330 roughly 7% less.
Weld penetration is likely poor in this design. Nickel alloys are difficult to get good penetration when welding. You may look at how you might get a better weld joint if possible in your design to improve the life of the component.
RE: Best suited material...suggestions????
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: Best suited material...suggestions????
I previously have used 600 series material (which was purchased from you). However price and availibility are
not what they used to be.( I realize that this is out of your control) My customer has asked me to
experiment with other materials, so that the price can stay where it is. I was previously using 625RA. This robot cycles 25,000 times a day. there are 22 of them. I will
heed your advice and go from here. Thank you for the very informative post!! KJC
Crowell Machine
Emporium, PA