×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Casting HSLA parts

Casting HSLA parts

Casting HSLA parts

Asteryx,any reason for considering the casting route? What is the part you intend to cast?
Will the foundry be able to handle the small batches? As in the case of plates,there is no grain refining or strengthening mechanism due to mechanical working for castings. For cast parts,it is essentially, grain refinement and microstructure control ( by heat treatment) that will enable you get the properties. I am sure you are aware of these.

Casting parts are likely to have internal casting defects,you must be able to identify and locate these defects . Determining the critical flaw size is important for your application alternately, a steel has to be chosen that has a large critical flaw size,so that it can be measured more accurately.  

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

RE: Casting HSLA parts

(OP)
The parts are arms on a device that will be subjected to both tensile and lateral loading.

The incentive is just design and weight efficiency; we want to design in geometry that does much more for strength and performance of the part than we can do with plate.

The competition does something similar with a good track record, although we're trying for slightly higher mechanical properties.

We've been casting ~G50 parts and are happy, and initial prototypes to that grade are good; we're just unfamiliar with casting the higher mechanical properties and what's going to be involved in getting there.

The parts range from about 2 kg up to 30 kg, and we will go much higher if feasible - up to about 150 kg. Lost wax investment for the small ones and sand for the big guys.

RE: Casting HSLA parts

Lost wax for the smaller ones is a good selection maybe up to 5 kgs.Chemistry wise,it is not difficult,you could adapt similar chemistries with some grain refining,which the foundry I am sure will know. Oil quench and temper the steel appropriately  You should be good,but please look for manufacturing defects in the castings.

Will the foundry accept to do small batches or is the alloy regularly being processed by the foundry.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

RE: Casting HSLA parts

In general, steel castings are spec'd to min mechanical properties and the chemistry, within a certain range, is left to the discretion of the foundry. Addition of a weldability requirement adds a further restriction to chemistry, mainly on carbon content. The heat treat process will be at the discretion of the foundry to conform to the mechanical property requirements.

RE: Casting HSLA parts

I doubt you can make a cast equivalent to these steels, since they depend on thermomechanical processing for their properties, foremost of which is very fine grain structure.  It may be possible to obtain the same yield and tensile properties using conventional alloys, but not the excellent low-temperature impact properties of HSlA steels.   

RE: Casting HSLA parts

Brimstoner--good point about the low temperature service requirement. What I took from Asteryx is that he wants equivalent strength to the HSLA material and he also needs weldability and, as you pointed out, low temperature performance. Castings can be made to do these things; it just gets more expensive than meeting just the strength level.

RE: Casting HSLA parts

(OP)
Thanks for the replies.

The requirement for Charpy CVN average is ≥ 34 J at -20 deg C.

Operating temps are as above no lower than freezing; will be used underwater.

Microalloy is on the notepad here too, but I understand elongation will suffer. Bending is a preferable failure mode for us than breaking... even if it has to be at a lower yield.

Swall we will talk to the foundries but just wanted to know what we're talking about to a limited degree before doing so.

RE: Casting HSLA parts

That Charpy requirement is not onerous; I'm sure the foundry has a recipe for you.   

RE: Casting HSLA parts

Just curious - that cast HSLA isn't a grade that would embrittle, is it, at the nominal 850F/454C temperature used for hot dip galvanizing?
In any event, the weldment should be stress relieved before hot dip to avoid cracking from molten zinc.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources