Understanding the Casting Process for High Strength Steel: A Guide for Beginners

[oremo123]

Hi,

I was wondering how to tell if a part is an ingot or continuously cast. I'm looking at a high strength steel. It's a part of a bulldozer and has some bolt holes. I was wondering if people could offer some guidance as to how I should proceed to figure out the processing steps taken to create this thing. Visually, it is rusted on top, but the part itself does not seem to be damaged. So I'm guessing some sort of hot working was done. I'm kind of new at this so any help would be greatly appreciated.

Thanks

 

[Astronuc]

I'm looking at a high strength steel. It's a part of a bulldozer and has some bolt holes.

That's not much to go on. It could be forged.

What is the component? And what are the dimensions? Do you know anything about the chemistry? Have you done any metallography?

brewnog might have some insight.

 

[oremo123]

Yeah, this is for a school project. Not given much starting information than that. I believe that we're supposed to provide a general outline as to the manufacturing steps, but I just wanted to where and how to start. The part is approx 10"x6"x3" and weighs ~30lbs.

I was just wondering if there's a way to look at a casting and determine if it's continuous cast or started from a mould ingot. The part was cut along it's width, and I saw that the grain were stretched in lines, which makes me think it was also rolled where all the grain boundaries were stretched into these straight lines.

 

[Astronuc]

Do the lines run along the 10" length? The billet may have been rolled.

Does one know the approximate date of manufacture? I think the trend in steel has been to move to continuous casting over the last couple of decades.

Also, does one an estimate of the grain size, length and width?

Can one determine a composition?

 

[brewnog]

Not much insight from me I'm afraid, I'm a manufacturing rookie. The lines you describe would certainly help to identify the process but we'd need to see pictures. Otherwise, Astronuc has got this one I think.

What is the part?

 

[FredGarvin]

I'm still in the dark as to what this part looks like. That will make a huge difference in how something is manufactured. Is it solid or does it have internal passages? Ususally, one dead give away as to whether something is cast is that the majority of the surface finish of the part is rather poor. Only limited faces and features of the part have machine finished surfaces. Also, split lines and lines that show where there was once flashing is also a clue.

So far though, with the descriptions you have given, it really is still not narrowed down to anyone method. Your description of the grain does indeed make it sound like it was a rolled item.

Is there any way you can post a picture or give a end use description of the part?

 

[Gokul43201]

Continuously cast slabs that did not use some kind of nucleus inoculation/stirring have a very characteristic columnar grain structure with the grain orientation perpendicular to the nearest surface (since the majority of nucleation sites are on the surface).

A picture of the part and of the grain structure is essential for us to help. General guidelines are somewhat hard to provide, short of throwing a Physical Metallurgy text at you. In any case, determining the fabrication history of a virtually unknown material is quite a challenge. What tools to you have at your disposal? Can you have spectroscopy done on a bit of the sample? What is the highest resolution microscope you can have (if casting porosity can be identified, that virtually rules out forgings)? And how about mechanical testing?

 

[lockey25]

hi,
Is somebody here a casting simulation engineer. I am in the processs of learning, the complete process of modelling it and am stuck with Interface heat transfer coefficient between the mold and the casting. I am using procast inverse method, but am having difficulty finding the solutions. Can you suggest an alternative software for the iterative calculation of the IHTC? If someone has used procast before can I be guided. I'm having trouble finding the range of this coefficient when gap formation starts and how to approximate useful enough values.

cheers

 

[Matcon]

I only got this as a throwaway comment from a steel company, but I think the distribution of inclusions would also be a clue. Inclusions would tend to form in lines ahead of the columnar grains mentioned by Gokul43201.