material ID

[snowcat]

anyone care to have a stab at what this is, wanted to machine up a couple of 45mm pins for a job im on, picked up what I thought was normal stock bar from the shelf, started to machine, and jeusss its hard, lots of very hot peal, no chip and id say there would be little chance without carbide tips.... finishes nice tho, spark test was short and dull.... it does not seam to work harden but I'm not gonna test that, suds gallore....

 

[Drains]

I couldn't even hazard a guess tbh... but, er, 24T?

 

[hareng]

Is that one of those Top Notch Kenametal tools?
All i can say is EN9 and EN42 come out like that.

 

[TechnicAl]

Jeez Snowcat you dont make it easy

If its over 300 Hv its impossible to machine even with the carbide tip. Its unlikely that anything over 250Hv would produce the spiral swarf seen on the photo.

Something like en24 / en9 / en16/ en19 / en42 could fit the bill if they were normalised or annealed but quenched and tempered would probably be too hard.

It looks stainless to me but thats probably because its shiny. Could it be free cutting stainless?

any more clues?

 

[snowcat]

Is that one of those Top Notch Kenametal tools?
All i can say is EN9 and EN42 come out like that.

yeahh kenametal all the way best investment I ever made was decent tooling..

Jeez Snowcat you dont make it easy

free cutting stainless?

any more clues?

easy me, you should know I only post stuff that stumps me

stainless nope,clues erm the ends were rusty, bar was black, erm band saw chopped it, rolled with a chisel rather than chipped, as I said doesn't appear to work harden, tock the edge from a center drill nicely so its pretty hard, ohhh and doesn't appear to weld at all well, brittle surface weld very poorly penatrated....

open to sugestions please

 

[TechnicAl]

In light of the new info Id guess it probably is something like en 24 but possibly softened so its machinable.

however ???????????

 

[snowcat]

In light of the new info Id guess it probably is something like en 24 but possibly softened so its machinable.

however ???????????

any idea what the breakdown of en24 be??? machined lovely, the statement about work hardening isnt true tho, a bit to aggresive in the drill evn with £40 cobarts and it was all over, ermm be intrested in what it is tho, ideal for machne pins......

 

[Drains]

OUr machine shop works en24T regularly. I just mentioned it to the foreman, he says it machines fine. The heat treated T isn't much different to the standard EN24 for machining purposes. They always send cranks etc for stress relieving before final machining, as it likes to move.

Certainly doesn't need to be softened to be machinable Al!

 

[TechnicAl]

En 24 is something like 0.4C / 0.5 Mn / 1.2 Cr / 0.3 Mo / 1.5 Ni so its a low alloy steel or another term would be Engineering steel.

It can be a bit of a pig to weld. The belt and braces approach is to preheat to 250oC weld 2 layers of 312 stainless on both faces and allow to slow cool (packed in sand or similar) then depending on the thickness weld the welded faces together, again using 312
If its over 25 mm thick its possible to get the 312 too hot so you need to be careful and allow to cool or if you dont need the strength you can use 308L.

Having said that I have known it to be welded with standard MS Mig and not crack but I would never guarantee it.

 

[TechnicAl]

OUr machine shop works en24T regularly. I just mentioned it to the foreman, he says it machines fine. The heat treated T isn't much different to the standard EN24 for machining purposes. They always send cranks etc for stress relieving before final machining, as it likes to move.

Certainly doesn't need to be softened to be machinable Al!

En24T is the softened condition. The hardness is around 250 Hv
The en24 V or W or X or Z goes from 350 to 450 (ish)

 

[Drains]

We live and learn!

Cheers Al.

 

[Drains]

Al, while you're about, I've a small problem needs an answer.
We have a 1.5 tonne hydraulic pump shaft from SAE 1045 Bright Bar (EN43B?), which has a small score on an area which will have a lip oil seal running on it. I would like to tig it up and file/stone back to shape. The score (due to bad handling) is no more than a mil deep, 4 mm wide and 100mm or so long.

I've checked the data sheets, and in theory "this should be fine" - (correct that - it should be lo-hi's), but this is a massive piece, already machined to fine tolerances. I really dont want to get involved in pre-heating, as we might as well just send it back for re machining and re-spec the oil seal.

So, my question is, can I tig fill with standard M/S filler wire, and no preheat. Should I then do everything I can to slow the cooling, or won't it matter?

Cheers
Si

 

[snowcat]

En 24 is something like 0.4C / 0.5 Mn / 1.2 Cr / 0.3 Mo / 1.5 Ni so its a low alloy steel or another term would be Engineering steel.

It can be a bit of a pig to weld. The belt and braces approach is to preheat to 250oC weld 2 layers of 312 stainless on both faces and allow to slow cool (packed in sand or similar) then depending on the thickness weld the welded faces together, again using 312
If its over 25 mm thick its possible to get the 312 too hot so you need to be careful and allow to cool or if you dont need the strength you can use 308L.

Having said that I have known it to be welded with standard MS Mig and not crack but I would never guarantee it.

I thought it might be a carbon Manganese steal, but looking at that analysis its not, I take it weld principles are similar tho.???

Corrrr get that Mr Drains and his thread hyjack

Ohhh would 7024s and preheat do the job, or a 307

I sort of remember the history behind it, got in because the Foreman of the works was insistent that he wanted weld on bosses made from it, to cut a long story short, they had such trouble with the welds cracking that they were whacking in em on with a MIG and M/S wire that they went back to EN or even 1A.....

cant find EN 24 to cross reference in my book, would it be BS 080A20??

 

[TechnicAl]

I thought it might be a carbon Manganese steal, but looking at that analysis its not, I take it weld principles are similar tho.???

I sort of remember the history behind it, got in because the Foreman of the works was insistent that he wanted weld on bosses made from it, to cut a long story short, they had such trouble with the welds cracking that they were whacking in em on with a MIG and M/S wire that they went back to EN or even 1A.....

cant find EN 24 to cross reference in my book, would it be BS 080A20??

BS970 : 817M40 is nearest to En24T

 

[TechnicAl]

Al, while you're about, I've a small problem needs an answer.
We have a 1.5 tonne hydraulic pump shaft from SAE 1045 Bright Bar (EN43B?), which has a small score on an area which will have a lip oil seal running on it. I would like to tig it up and file/stone back to shape. The score (due to bad handling) is no more than a mil deep, 4 mm wide and 100mm or so long.

I've checked the data sheets, and in theory this should be fine, but this is a massive piece, already machined to fine tolerances. I really dont want to get involved in pre-heating, as we might as well just send it back for re machining and re-spec the oil seal.

So, my question is, can I tig fill with standard M/S filler wire, and no preheat. Should I then do everything I can to slow the cooling, or won't it matter?

Cheers
Si

To guarantee it wont crack I would say you have to preheat, its up to 0.50% carbon so its highly susceptible to cracking.

As its TIG (so its very low hydrogen) which puts a lot of heat in, I would give it a go. The stresses involved in filling a hole are a lot lower than those in a butt weld etc. If its no good anyway you might as well take the chance.
I would fill say 10mm leave 10mm and fill the next 10mm. Sort of like stitching, then go back and fill in the spaces. That would reduce the stresses even further.


Oh and Good Luck

Let us know if it works

 

[Drains]

To guarantee it wont crack I would say you have to preheat, its up to 0.50% carbon so its highly susceptible to cracking.

As its TIG (so its very low hydrogen) which puts a lot of heat in, I would give it a go. The stresses involved in filling a hole are a lot lower than those in a butt weld etc. If its no good anyway you might as well take the chance.
I would fill say 10mm leave 10mm and fill the next 10mm. Sort of like stitching, then go back and fill in the spaces. That would reduce the stresses even further.


Oh and Good Luck

Let us know if it works

Thanks Al, just the answer I was looking for... The area to be welded is not under any stress - this is a very bulky bit of kit, and stresses will be in another part entirely. I'll post a pic later, for interests sake.

The alternative fix was to gouge out the score and fill with metal putty, which might work but means grinding, right next to a very large and expensive bearing race. Too much crud to get in the works. Can't bin the shaft and start again either - cost £13K.

Edit - Snowy, thanks for lending us yor thread

And Al, a Star as ever!