rods placed into cast to use as lifting attachments

[kingnero]

I remember a thread on here not too long ago (1-2 years?) about rods, placed into the moulds before pouring steel, to be used as lifting eyes.
However I cannot find the thread.

I was wondering about the materials used for this. I have been asked to propose a solution for a similar problem, albeit lower temperatures (900 - 1000 °C pouring temp, that's 1650 - 1850 °F).
Also, as I'll be doing the strength calcs, if it's a hardened steel (?), what should I used for yield and shear strength, as I suppose the material's mechanical properties might degrade in such temperatures?

 

[arunmrao]

@kingnero,

Referred thread was started by me for a 10ton ballast weight. I cannot find thread reference for you. It must be in Mechanical Engineering forum.
The cast material was grey iron and rods for lifting were made of 304 stainless steel. 2 rods of 75mm Diameter and about 350- 400 mm long were placed in the mould and cast.

Subsequent handling of the castings using the rods never posed any problem

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[kingnero]

Hello Arun,
Thanks for the quick response.

Why did you choose for a stainless steel? Were there any special corrosion requirements?
Would an "chromoly" steel (e.g. 41xx) not be cheaper, or would this for any reason not be suitable?

Edit: now I found the thread, knowing you were the one that posted it:

https://www.eng-tips.com/viewthread.cfm?qid=422479

You said: "Also using SS pin cast in situ is the industry practice ." OK, if that is the case, I believe there is no need for me to deviate from this.

 

[arunmrao]

I chose stainless steel as the casting was used near the sea coast. You can definitely consider 4130 steel . It is certainly cheaper and I am sure, will serve the purpose.

In the past,I had used mild steel hooks for a 3 ton cast iron sinker casting ( 300 numbers) used in marine industry. These castings were dragged and dropped in the sea.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[kingnero]

Thanks for the additional information. However 304 would also be my first choise, as the casting will be lifted with fabric slings instead of chains. Stainless will be easier for the fabric than steel.

Just out of interest, would the prolonged stay at high temperatures (while the casting cools down) significantly change the mechanical properties of a 4130 rod?

 

[arunmrao]

"Just out of interest, would the prolonged stay at high temperatures (while the casting cools down) significantly change the mechanical properties of a 4130 rod?"

In my experience, I have seen no difference though some might argue against it.



"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[kingnero]

Thanks again.

 

[BrianGar]

Just to add to this - I have seen a fair few boat tie offs being cast - the metal rod that gets placed into the mould core prints is always from what Ive seen (no matter what shape) first blacked with soot from a acetylene torch. The soot barrier aids in thermal shift as the two cool at different rates. I'm guessing if you didn't want to use a sooty torch setting, that you could also use core blackening paste such as GZA4 to do the same job. It is a zircon/graphite super fine powder suspended in Iso alcohol and is flamed off to dry before placement.

Brian,