SAE 1006 v/s SAE 1008

[ban7rjg]

Hello

Recently we have changed the supplier for the rotor claw poles of an automotive generator.
earlier MAT was equivalent of SAE 1006.
new MAT is equivalent of SAE 1008.

Current output is low with the new MAT.

Kept constant: All Design parameters
Changes: A slight process change by the new supplier
MAT change

Can anyone suggest why?

Thanks

 

[EdStainless]

It has to to either with other elements in the steel, not just C, or it is the heat treatment.
You need to test magnetic properties to figure it out.

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Plymouth Tube

 

[ban7rjg]

For a DC application like this, magnetic properties imply:
1. Saturation point
2. B-H product
3. Permeability
Apart from these, what else must I look at?

 

[dgallup]

How do you manufacture the claw poles and do you anneal them?

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[EdStainless]

In a soft magnetic material you look at permeability and saturation.
You may need to look at perm at a specific applied field strength.

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Plymouth Tube

 

[MagBen]

if at the same annealed status, 1006 is supposed to be very similar to 1008. Running a B-H curve, you will get everything for DC.

 

[ban7rjg]

@ MagBen
@ EdStainless
Thanks for the inputs.
In fact we will be plotting a B-H curve soon. However, are there any specific 'boundary conditions' to be defined for conducting the measurement?
Last time I interacted with a guy who does B-H curve plotting he bombarded me with questions pertaining to these 'boundary conditions'.....of which I have little knowledge.
Any suggestions?

@ dgallup
We drop forge the claw poles.
Annealing is done for the SAE1006 parts but not for SAE1008.

 

[dgallup]

"We drop forge the claw poles.
Annealing is done for the SAE1006 parts but not for SAE1008. "

Well you should not have far to look to find the problem.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[ban7rjg]

@ dgallup
Yup, I agree that annealing gives the desired results. However, it costs.
While using the SAE1006, I am additionally trying to cut this additional annealing cost.
Any suggestions (like partial magnetization during processing, etc)??

 

[EdStainless]

Annealing these should be costing pennies a pound.
A good anneal is the only way to improve the magnetic characteristics.

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Plymouth Tube

 

[ban7rjg]

Thanks to everyone for their valuable suggestions.
I will look in this direction and let you all know what the results are in a few weeks time.

CHEERS!