EN32B Steel

[JasonBModerator @jasonb]

One problem with a list like that is that having one general purpose steel will give you difficulty when you come to buy in different sections.

General purpose round is usually EN1A (230M70) but if you want a general purpose flat or square bar that is most likely to be sold in EN3 (080A15) or if you wanted hex then the usually stock is EN1A Leaded (230M70PB).

There are a few exception where you may get EN1A square for example but the choice of size is less particularly if you still want imperial sections.

A look through Parkers bright steel selection in both metric and imperial gives a good idea of what is available from a large stockist if you click the product matric for the chosen section it give size and metal types and a link to the paint colours is there too. Smaller stockholders will keep less and ME suppliers even less choice.

[Anna 1Participant @anna1]

Hello Dave.

I cannot say that I have read all of the report that you linked in your post, however as far as I could see the report relates only to non metallic inclusions, and makes no mention of possible problems with metallic inclusions or give steel a clean bill of health on that count. Please correct me if I am wrong. It is interesting further down the report that Ravenscraig seems to come out with a fairly clean bill of health.

I do not think we all are imagining that there is a problem with the currently supplied steel.

Re, parts of ball bearings etc. in steel. I cannot say I have seen that. However, in a former life I was persuaded against my instincts to injection mould some recycled polypropylene. Part way through the first bag I discovered a large broken spring which had fortunately attached to a ring of magnets in the base of the hopper If it had reached the screw it would have caused some very expensive damage. I learned a lesson that day, using outside sourced recycled material could be a very big mistake. kind regards Anna

[John FlackParticipant @johnflack59079]

Slightly off topic….I am old enough to remember he railings and gates being removed for the "war effort" This was followed by a horse and cart collecting mums spare saucepans, the rumour was for spitfires!!

Some years later in my national service I found myself blasting away with a 3.5 inch rocket launcher(don't dare to call them a bazooka) punching holes in defunct military tanks on Luneburg Heath, in Germany, it did occur to me at the time that they might have been made from my parents old railings.

I guess that quantity rather than quality was the order of the day then……………perhaps it still applies!!!

[SillyOldDufferModerator @sillyoldduffer]

Posted by Anna 1 on 19/12/2017 12:49:59:

Hello Dave.

I cannot say that I have read all of the report that you linked in your post, however as far as I could see the report relates only to non metallic inclusions, and makes no mention of possible problems with metallic inclusions or give steel a clean bill of health on that count. Please correct me if I am wrong.

…

However, in a former life I was persuaded against my instincts to injection mould some recycled polypropylene. Part way through the first bag I discovered a large broken spring which had fortunately attached to a ring of magnets in the base of the hopper If it had reached the screw it would have caused some very expensive damage. I learned a lesson that day, using outside sourced recycled material could be a very big mistake. kind regards Anna

Hi Anna,

Yes, the report is about non-metallic inclusions. I found it (and similar material) while looking for evidence of metal objects found in steel. I didn't find any evidence of those.

The report's significance is that it explains the presence of hard inclusions without requiring a ball-bearing or a lump of HSS to somehow survive unmelted in a furnace heated well above steel melting point. A huge amount of energy is needed to react out impurities and a big furnace can process as much as 30,000 tons of steel at a time. Although I feel metal inclusions are unlikely to survive that environment, the process damages the furnace and subsequent handling can also introduce problems.

Though I'm sure hard spots are a real problem I doubt they're caused by incompetent manufacture. Nor are they new – complaints about steel quality are as old as the hills. Ordinary cooling and rolling etc. can also cause problems. Perhaps this cause of hardness is even more likely than an inclusion – it's difficult to cool a large lump of metal at the same rate throughout. Normalising fixes it, a process that's been about for centuries.

When it really matters, say making a nuclear reactor's pressure vessel, steel-makers can guarantee their output to high standards. Careful selection of materials, extra careful chemistry, clean processing with an electric furnace full of Argon, and elaborate testing are all effective. Shame about the cost!

It's far more likely for unwanted objects to turn up in other recycled materials (and in food!) The processing isn't very intensive and might include error-prone hand picking. Or corner cutting to save money. When it really matters you have to be careful what you buy and check everything.

Dave

[Anna 1Participant @anna1]

Dave,

Thank you for your reply.

Just out of interest over the past few days I have been machining some steel (en3b) and have found what look like very fine hair line marks (fissures?) in the machined surface very similar to those shown in the report just discussed. I cannot say I have ever seen that before.

Regards Anna

[ChrisHParticipant @chrish]

Clive – I did say it was tongue-in-cheek, it was playing with letters to achieve a comment. I am aware of the origin of EN numbers.

What would be good is some standardisation of what all suppliers call each product. Some will say EN1A, others will only answer to 230M70 for example, both are arguably the same product.

I also appreciate that odd hard bits can and do get found in all sorts of types of steel at random intervals and that the problem is a very old one. I can never legislate to avoid ever getting a bit of steel with a hard bit in it, but I can try and ascertain what other folks do to get round the problem and use that knowledge to help myself deal with the problem when I experience it, which is what this thread is all about.

Chris

[duncan webster 1Participant @duncanwebster1]

Lots of model engineering suppliers quote 'GCQ' when asked what steel they sell. this means 'I've lost the cert, or I didn't understand it so I threw it away'

[Neil WyattModerator @neilwyatt]

My local stockholder have a computerise inventory down to the stubbiest of short-ends, but ask for 230M70 19mm and you will get 3/4" EN1a – in a three metre length, of course…

Neil

[vintagengineerParticipant @vintagengineer]

I use a very good local steel merchant, I tell them what I want the steel for and they tell what I need. Some times it's an EN number sometimes it's a BS number. Best policy is find a merchant you can trust and don't worry to much about the cost.

[Mark RandParticipant @markrand96270]

I used to have a very good steel stockholder (Macreadys in Rugby), but after a couple of takeovers, their replacements only stock a limited number of alloys and have a minimum 1 tonne per size policy. I used to be able to buy full bars of all the normal alloys and heat-treats (EN1A, EN1APb, EN3, EN8, EN16T, EN24 and EN24T) and less-than-full-bar when the diameters got up to 4". It's annoying, since they are only a mile away from home, but the downsizing of my (ex) employers in the town from a total of 10,000 to 1,000 over the last 35 years might have something to do with it…

Now I use Parker Steels (who are over an hundred miles away) and still try to buy minimums on one bar of any size. Ok the kids might have a selection of steel stock to use/dispose of when I go to meet my maker, but I can't see the point of buying the odd foot of steel unless that length is already too heavy to lift easily. Steel gets an awful lot cheaper if you can buy enough of any size to keep you going for the rest of your planned lifetime.

Back to the point:- I have met up with work hardening when not cutting aggressively enough or cutting an unknown alloy. I have wrecked carbide milling cutters in black mild steel plate when using them for work that a bandsaw was better at. But I haven't, yet, met a hard spot in a full bar of a known alloy. Some of the bars that I've bought have shown signs of being at the start or end of the run. Those bits are obvious and can be discarded.

Edited By Mark Rand on 20/12/2017 00:45:12

[JasonBModerator @jasonb]

Posted by Mark Rand on 20/12/2017 00:43:33:

Some of the bars that I've bought have shown signs of being at the start or end of the run. Those bits are obvious and can be discarded.

Or sold off to Model Engineers on ebay

[ChrisHParticipant @chrish]

Ooooh errrr! I had chance yesterday for shed time, so lite the fire in the shed stove, got it going well on smoke-less, chucked the tool holder with the hard bit in, threw some more coal on top, saw it a wee while later all – including the metal – very much glowing nicely (very) red and left it to burn through and cool down overnight. This morning I pulled the metal bit out the ashes and; Oh my word, I didn't expect this: – see photos below.

I chipped all the scale off and revealed what could be expected – the metal underneath was very rough. Set it up in the mill and tried a facing cut off one side with a flycutter and promptly blunted it, so, unwilling to sacrifice another milling cutter it now looks like I have another useful door stop. Another item now on the next metals order!

Chris

[duncan webster 1Participant @duncanwebster1]

Might be a silly question, but here goes. To carburise something you bury it in carbon (kasenit, button dust, sugar etc) get it red hot and keep it there whilst the carbon diffuses into the surface layer. To anneal something in your coal burning stove you cover it in carbon and get it red hot……… See where I'm coming from?

[ChrisHParticipant @chrish]

Yes Duncan, that did occur to me after, and not a silly question. Perhaps it might have worked if I had covered it in SS shim, which I have, before placing in the coals, or if I'd been able to fabricate some means of holding it above the coal. That process not thought through before I went for it!

Both alternatives have given me fuel for thought for the future though. What it has proved is that in my stove I can heat a really considerable lump of metal up to red hot glowing temperatures and hold it for a while, hours, if necessary, which I didn't think I could do, so that is progress in one direction. I had sort of given up on the lump anyway really. Now I know I can do it, the next stage is refining the process to get it to work for me, whether either annealing or case hardening. Wrapping an item in SS shim packed with carbon of whatever extraction and 'cooking' it in the fire or arranging a removable rack to place objects to be annealed or case hardened on is a reality to explore! Quite like the rack idea.

Had I an electric furnace all would have been easier but I don't now the money to buy one, even if I had ever seen one advertised which I haven't, like where do you scource cheap electric furnaces except perhaps ebay?

Chris

[duncan webster 1Participant @duncanwebster1]

Posted by ChrisH on 21/12/2017 22:16:14:Wrapping an item in SS shim packed with carbon of whatever extraction and 'cooking' it in the fire or arranging a removable rack to place objects to be annealed or case hardened on is a reality to explore! Quite like the rack idea.

Had I an electric furnace all would have been easier but I don't now the money to buy one, even if I had ever seen one advertised which I haven't, like where do you scource cheap electric furnaces except perhaps ebay?

Chris

maleable iron electrical fitting or other steel box would be the traditional approach, SS shim is too valuable, and prone to leakage to use as wrapping paper.

Hint Neil, article on making an elctric muffle needed.

[JasonBModerator @jasonb]

Re the carbon comments, this is why it is always suggested to cool as slowly as possible. If it does take on carbon and you take it out the fire and quench it that is just like hardening with kasamite, leave it too cool slowly and you end up with steel in it's unhardened state.

Might have been worth pickling the part to remove the abrasive scale before you tried to cut it again.

[MuzzerParticipant @muzzer]

Posted by duncan webster on 21/12/2017 21:15:49:

Might be a silly question, but here goes. To carburise something you bury it in carbon (kasenit, button dust, sugar etc) get it red hot and keep it there whilst the carbon diffuses into the surface layer. To anneal something in your coal burning stove you cover it in carbon and get it red hot……… See where I'm coming from?

The atmosphere around the latter contains significant amounts of oxygen (and nitrogen) and any carbon is presumably in the process of being oxidised, rather than trying to diffuse into the surface of the steel. Which is why the former process requires to purge and exclude external gases and maximise direct contact of carbon with the surface. The carburisation process requires temperature, time and a significant concentration of carbon on the surface of the steel. Although there are some related processes that rely on hydrocarbons etc for surface treatment, those processes tend to be very complex and challenging to implement.

Murray

[ChrisHParticipant @chrish]

The use of stainless steel shim suggested itself from a video on Tom's Techniques website when he was case hardening a small part. He wrapped the small part complete with case hardening material in SS foil which he got from some craft shop/website. I couldn't seem to source it this side of the pond and thought SS shim, I have it in various sizes to 6 thou, would do (not done it yet!). You do have to fold it over and over and crimp it best as can to exclude the air, and he recommends putting in the parcel a little combustible material to deliberately burn and consume the oxygen remaining in the ss foil wrapped parcel. Not sure how thick the shim would have to be, too thick and it'd be a swine to fold and crimp air tight, too thin and I suspect it might burn away in a really hot fire.

Now an article in MEW on building a simple electric furnace would be very interesting, so +1 on that idea Neil!

Chris

Edited By ChrisH on 22/12/2017 14:59:51

[Mark RandParticipant @markrand96270]

I made an electrically heated salt hardening furnace some years ago. It lasted long enough to do what I needed it for, but it wasn't all that safe and the heating element got a hot-spot and melted soon after. It's here if anyone's interested:-

**LINK**

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