Steamingandy
Well-Known Member
Has anyone come across this it looks like a stain and won’t machine or polish out it’s cast iron Meehanite bar I can’t really take much more material off wondering if it’s going to have to be binned
Do you know WHERE this was manufactured and HOW it was manufactured. That might give us a clue.So I have turned the other end and the pattern is mirrored exactly 2” down the bar?it must be a production issue otherwise it would be random View attachment 131955
It's probably spun-cast - was done with the melt at too low a temperature - the "pour" proceed unevenly but in regular gulps and produced a helical pattern in the bar which also looks to be temperature shocked and possibly even improperly fused.
This process can also produce long epitaxially grained and corkscrewed core grain structure which is near impossible to drill straight.
I wouldn't use that material for anything important.
Normalising heat treatment might fix it - but I would still be suspicious of it's structural integrity.
Regards, Ken
More likely continuous cast, that's how Dura-Bar does it and the striations on the unmachined part suggest that's how it was cast. The continuous casting process | TassoBar As for the integrity of the bar, I agree with Ken.It's probably spun-cast - was done with the melt at too low a temperature - the "pour" proceed unevenly but in regular gulps and produced a helical pattern in the bar which also looks to be temperature shocked and possibly even improperly fused.
This process can also produce long epitaxially grained and corkscrewed core grain structure which is near impossible to drill straight.
I wouldn't use that material for anything important.
Normalising heat treatment might fix it - but I would still be suspicious of it's structural integrity.
Regards, Ken
How about if you cut it into 5/8" slices? each slice would be uniform, at least till you reach that unstable region. I could use it to cut into 5/8" squares as I need to make some 1/2" rounds about 3" long. Would sections of it be OK?Probably rejected from a production lot, sold off as scrap, and you wound up with it. If you can, return it. If it WAS scrap material, then just get rid of it. It will be causing you problems every time you use it for the next 30 years.
Can you tell me how a spin cast mould works?I think you will find that defect is a continuous corkscrew and no slice will be free of it.
Steelworks typically re-melt all scrap - they buy scrap - they don't sell it - but that doesn't stop them producing rubbish.
I don't believe it is continuous cast - those longitudinal striations are from ejecting it form the spin casting mould. Continuous casting is drawn out by rollers, typically drawn out round, then rolled square and reduced in size as a square bar down to required cross section, then formed up into a rhombus and made round only on the final mill-stand. This would look like any typical "black-bar".
Regards, Ken
Altho' I have had similar experiences, I have also been able to get very low priced scrap material that has been easy to work with and did what I wanted it to do. For the low price, IMNSHO, it is worth the few times I get material that cannot be workt in comparison to the good stuff I can get. I live in a small town that has a lot of manufacturing in it and I get scrap prices from some of their rejects. I have a VERY good idea what the metal is because of that./ I don't live near a nuclear plant either. I have seen 2" X 4' X 10' pieces of scrap stacked 20 pieces high. Quite frankly it was unbelievable to see this, but I saw it with my own eyes. Naturally just one of those pieces would most likely crush my pickup truck so I didn't get one. Also, even at scrap prices, I probably could not afford it. However, there were pieces of scrap that had been laser cut outs and the guys were cutting them into smaller pieces. I bought some of those--they were only 1-1/2" thick. Ive been using them for a couple months now. They are high quality mild steel, easily cut on the lathe and mill. I'm using them to make the tools to make the tools to make parts with. A couple of those tools are plates that fit the nose of the lathe for ER collets.I once needed some stainless steel large diameter tubing. (Like 4" OD.)
I finally found some at a local scrap yard, and I think I paid $10 for it. This was back in the 1980's. That stuff was an absolute ******* to turn or machine. I eventually gave up, and it is still resting against the wall next to my garage door, in the small space between a workbench and the wall, in case I ever need such a tough material. My assumption now is that it was part of the material scrapped out of the construction of the Palo Verde Nuclear Plant, which is west of Phoenix. Arizona. There was no other exotic material type project that I can think of where they would have used such a material in Arizona. And it would not have paid to truck it as scrap from anywhere like Los Angeles or New Mexico all the way to Tucson. So there it still sits, over 40 years since I first bought it, and never of any use to me. That totally cured me of buying unknown materials of ANY kind. Anything unknown is a good candidate for problems. I have enough of those just doing machining, I don't need any more from the material I am trying to use.
Further confirmation of this good policy was my acceptance of what I was told was Kirksite, a material that is a low melting allow, that you can form in a plaster mold, and then stretch sheet metal over it. It turned out to be just aluminum slugs. I have no idea where the original owner thought it was actually Kirksite. Fortunately, it was free, but it still reminded me not to bother with ANY unknown material.
Buy what you need, and machine happily. Or only accept stuff if you KNOW what it is, such as cast iron, brass, etc.
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