440C and 15-5ph BH-curves 2

[magnetrics]

I am currently working on DC motor design and i am confronted with the problem of unavailability of magnetic steel in my country for my design, I'm from the Philippines. I tried contacting cartech but they said my order is too small for them. But i have available stainless steel in my backyard with grades 440C and 15-5ph. They are magnetic though I can't effect them in my design because I don't have a data with regard to their specific DC magnetization curve characteristics.Can anybody in this forum tell me where to get a data on this stainless steel alloys so that i can proceed in my design. Thanks a lot.

 

[remetaper]

About 15.5PH, you can find a good explanation and a technical paper in "Metal and Metallurgic eng.forum " at April ,9 , 2009.
You consider that 17.4PH is a "brother " of 15.5PH when its chemical composition shows a lower Cr/Ni equivalent. However, if you found any difficulties or need explanation, don't exitate to write again.
About 440C,you have to decide which kind of heat treatment you need even if I woud exclude the annealed condition.
In hardened + tempered condition, its magnetic permeability and coercive force manly depends on its Hardness, the amount of retained austenite ( double tempering or cryogenic HT +tempering ?). I think it is difficult to find magnetic data for this grade. However, I don't think could be so expensive to find a Laboratory in order to do a DC magnetic testing. You steel supplier could give you these values but-obviously - you have to require before order.
If I found any data about 440C , I will write in this forum.
Best Regards

 

[magnetrics]

remataper;

Thanks for your very kind reply. I appreciate it. I tried to check the forum last april 9, 2009 under the headings of metal and metallurgic eng forum but i can't find a relevant topic to my concern, instead I have seen something about 17-4ph topic last April 30,2009 under the same heading.

I have seen the producer's technical data sheets but it only described 17-4 ph as magnetic but as regards to its details, i didn't find any. Hope you can share some other sources if you know some. The Magnetization curve is extremely important for the design because its where I base all dimensions mechanical and electrical. Thanks you

 

[remetaper]

Try in this Magnetic eng forum where you can find at 9,April 2009 an thread "Magnetic permeability values " and a technical paper about 17.4.PH, 15.5PH and EN 1.4418 coming from a "Stainless Steel Conference , Sevilla,Spain 2005).
This paper explaine the behaviour of the above grade in terms of magnetic and mechanical properties and the reason why 15.5PH has lower magnetic properties ( permeability and Hc) at any aging temperature ( from H900 to H1150 )
As you will verify, you have to decide which kind of heat treatment condition you prefere.
In case you need B-H curve ( or values di B at a certain H) you could ask the Autors to give you B-H curve ( or values of B at certain values of H. Probably, they have no difficulties to supply.
Let me know if you need some more explanations/info and so on.

 

[israelkk]

The problem with the use of these alloys is that the magnetic properties are not guarantied. They have larger hysteresis curve and their properties are inconsistent for different material batches.

 

[magnetrics]

Thanks remetaper. I have tried contacting the author. update you later.

 

[magnetrics]

i was reading the technical paper on soft magnetic properties of 15-5 ph and i realized that the magnetic permeability for this alloy is way down low, existing at around 50 to 180....something only. With this range in values of magnetic permeability, I dont think it would be practical to use it as magnetic flux carrier because for obvious reason of economy,it's too costly in terms of material and electrical energy.

But I'm still open for any idea of anybody in this forum if this data on 15-5ph regarding magnetic permeabilty is true based from other experiences? Is 440C a better alternative then?

 

[remetaper]

Magnetrics,
which values of magnetic permeabilty, mechanical properties and resistance corrosion do you need ?
Grades of technical paper are PH and soft-martensitic steels (not soft magnetic steel as the ferritic ones 430 or 430F)
Therefore , you have to decide and, then, there is a lot of steel grades to choice and a lot of guys in this forum who could help you!

 

[magnetrics]

Remetaper,

I am looking for any steel which has magnetic permeability of around 3000 to 150 at saturation. Magnetic flux density saturation level should be at around 17 kilogauss at around 100 Oe magnetizing force.That is of course making use of magnet steel alloys like Ni-Fe, Silicon-iron, Fe-Co or just like what you've said 430/430f. But then I am at a loss on where to buy 'em because non of these alloys are being manufactured nor sold in my country as far as i know. i think i am the only person making such kind of project in the whole country today!(just kidding). What is available to me right now are a handful of 15-5ph and 440c bar stocks so i was planning to make use of them should they have magnetic permeability ranging from 1500 to 100 at least but then as i was looking at the works of those guys from valbruna steel company, they have shown that the PH and soft martensitic steel grades no matter what level of Cr/Ni equivalent ratios, their magnetic permeability are generally low, unless if you have some dissenting opinion on this matter!

I am thinking maybe there are anyone else in this forum who are making use of magnet steel alloys like I've mentioned above and if you have some extra materials maybe you can send it to me. Just let me know so I will make arrangements with you. I'm willing to pay if there are any.I just need small volume of material because it's purposely for a prototype project.

My friend Remetaper, maybe you you could help me out again if you don't mind by referring me to someone you know who has magnet steel alloys with them.Maybe I can ask from them if they are willing enough to share.Thank you!

 

[remetaper]

Magnetrics,
probably it depends on mine and your poor english but I need to clarify some subjects
1)I'm only a old metallurgical technician and I have never sold steel. Therefore,I'm not a commercial guy.
2)I don't understand if you must use the 15.5PH or 440C that you have in your yard or if you can buy different grades if these ones were available in your country or in other one.In both cases, your problem is the small quantity because neither Cartech nor other steelmaker wants to supply. Am I right ?
3)You said you are in contact with the Authors of paper. I hope they will give you some help because, usually, this Steelmaker is habit to supply information about his grades.Waiting for these data , I seem you could find some first info also from the paper. Particularly, you can verify magnetic permeability reach the maximum ( from 100 to 150 approx ) at H1025 (550°C)at any value of Cr/Ni eq.
Moreover , you can verify Jsat is between 1,3 and 1,6 T ( for 15.5PH you have to consider close to 1,3 than 1,6T)
4) If you are forced to use the 15.5PH, the first thing to do is:
a)to verify the certificate of the Steelmaker: which condition? If cond A,you can do a aging at temperature you prefere remembering that the maximum permeabilty will be reached at H1025 ( 550°C)
b)From the chemical analysis of certificate, you could foresee the values of mag.perm. by Cr/Nieq.
5) About 440 C, I have some data but I need to know if you want to use as annealed or as H+T . In this last case, mag.perm will depend on amount of retained austenite and Hrc. However , in both cases , Mag.perm = 65- 100.
Annealed condition is higher but this grade is not use in this condition.
Finally, if you decide to find and buy different steel grade, there is a large choice but it's mandatory to understand if you want stainless steel and its mechanical properties. Otherwise, we will continue to discuss whithout conclusion.
And if the Authors gave an answer, you could ask them if they could supply other data for different grades.
Let me know. Probably you are lucky !

 

[magnetrics]

Remetaper;

Here are my answers to your question.

1) Its not mandatory that i will use 15-5ph or 440c. it just so happen that they are the available scrap materials i have right now so i was just thinking if how i can make use of them.

2) Yes,I want to buy high performance magnet steel alloys like Ni-Fe, Si-Fe, Fe-Co-V alloys but they are too expensive for me as just an individual designer. Besides, my project is just a prototype that's why i need small quantity and Cartech for example cant just sell me a small volume.

3)I am not interested about the mechanical properties of stainless steels. I just need any steel alloy, not necessarily stainless steel, with high permeability(3000 to 100)with high magnetic flux density saturation level at 15 to 17 kilo gauss.

i want to buy any steel grade with high magnetic performance but of course at minimal price. Can you refer me to a supplier with minimal price?

Thanks!

 

[israelkk]

How about AISI 1010, 1018, 1020?

 

[magnetrics]

israelkk;

I came across with some related literature about low carbon steel grades 1008,1010,1018 and 1020 and yes, they have good magnetic properties too. So I have also gone browsing the internet hoping I can find a supplier in my country for these steel grades but to no avail, I haven't found one. Most if not all are into construction steel which are high carbon.

I have a question if you don't mind, in the reference book i'm using, it made use of the B-H curve of a cast steel as the magnetic material for illustration. In fact, it's where my intial design was based from. But then its not clear to me what is the exact description of cast steel as to chemical composition of this alloy is concerned. When they say cast steel, is it a particular form of steel alloy or just a general term referred to a group of alloys?

I know of foundries in the country making cast steel but then they don't divulge to me the chemical compositions of the said cast steel so i can't judge if they are magnetic or not.

 

[dgallup]

Is 12L15 is available? It is widely used for all kinds of machined parts. It will work for your purposes.

 

[magnetrics]

Sorry,12L15 is unavailable.

 

[remetaper]

magnetrics,
in order to verify if you have found what you are looking for about 15.5ph steel grade in terms of magnetic properties, did you solve your magnetic problem ?
And about 440C as well?

Have you any info about any B-H curve and Hc of 15.5 ph and 440C too ? In case you have, I think it could be a general good information for technical people of this forum. There is not a lot of test about magnetic properties of this grade at different heat treatmet condition. Therefore , any more data , it could be a "little step" for this forum.
In other words,I'm not talking about soft magnetic alloys or stainless Ferritic grades , Silicon-Iron , Ni-Fe alloys ... and so on where all people knows is able to looking for and find out several magnetic properties data.

Remetaper