A cast steel channel to substitute an extruded one
A cast steel channel to substitute an extruded one
(OP)
I have been asked by a customer to explore the possibility of substituting a U section channel wall thickness 8 mm and 2000mm long by a cast product. This is used in a medical equipment over which is fitted the rack for sliding the bed.
As the quantity is small sourcing such a product is difficult also forming by bending a sheet has not produced good results. a flatness of 0.5 mm across the length is expected.
I plan to cast a channel with extra stock and later machine all the faces to the required dimensions. I shall be checking ultrasonically for any defects.
I would like to know the precaution to be taken in using such a product and will it ever fail catastrophically( a scene I do not want to imagine).
As the quantity is small sourcing such a product is difficult also forming by bending a sheet has not produced good results. a flatness of 0.5 mm across the length is expected.
I plan to cast a channel with extra stock and later machine all the faces to the required dimensions. I shall be checking ultrasonically for any defects.
I would like to know the precaution to be taken in using such a product and will it ever fail catastrophically( a scene I do not want to imagine).





RE: A cast steel channel to substitute an extruded one
What kind of alloy are you talking about and what are the exact dimensions?
RE: A cast steel channel to substitute an extruded one
RE: A cast steel channel to substitute an extruded one
I wish you good luck and hope you quoted enough.
RE: A cast steel channel to substitute an extruded one
Is possible to find mechanical tubing close enough to your dimensions and machine it?
RE: A cast steel channel to substitute an extruded one
thanks for your encouraging response. I have a difficult task cut out, but considering the fact I may be considered for future casting requirements I am going through this grind. However, what are the pitfalls I might encounter,please advise .
RE: A cast steel channel to substitute an extruded one
the holding of the work piece and the stress set up while machining. As mentioned straightening along with stress relief maybe required for the part. I would look for having to do an intermediate stress relief after the “hogging cuts”prior to final straightening and machining.
I see you know a little about he foundry side so this maybe redundant. On quite a few of our WCB castings we normalized and tempered after casting prior to machining especially were there was requirement for tight tolerances and stability.
Good luck and let us know how it looks when you break the mold.
RE: A cast steel channel to substitute an extruded one
RE: A cast steel channel to substitute an extruded one
RE: A cast steel channel to substitute an extruded one
Thanks for your helpful comments. I have just opened the mold and cleaned the casting. It has come out with very less bow(1.5mm max). I can handle this as there is adequate machining allowance. Next task is the difficult one ,machining and maintaining the dimension.
RE: A cast steel channel to substitute an extruded one
Congratulations on a task well done in a record time.
That was nice casting job and as you stated that amount of bow is very manageable. Now stay on top the machinist and keep the tools sharp.
Thanks for coming back with a progress report.
RE: A cast steel channel to substitute an extruded one
Well Arunmrao, how did it end up?
RE: A cast steel channel to substitute an extruded one
the casting did not have any camber or bend. Also the machining did not pose much problem. I finished off the job with grinding operation.
RE: A cast steel channel to substitute an extruded one
The foundry industry can use successes as these.
Can you give a hint on the gating and feeding system you used?
RE: A cast steel channel to substitute an extruded one
I have used side feeders of 2.5in diax4in ht. 5 such feederwere placed along the length equally spaced. For gating I used finger gating,with runner bar all along the length of the casting. I poured manually(normal practice for me) simultaneously at both the ends. This ensured proper fill and the side risers avoided hot spots on the top face of the casting. Thus even while cutting the feeder there was no bend. An additional feature was that i had provided 5 internal tie bars of 10mm thick ,these were subsequently removed by machining.